jensplatta

For Europe in general, nothing compares to Madrid, Barcelona, Paris and  Berlin in terms of quantity, range of options and accessibility.
Athens is reasonably hard work but cheaper. However,  it can't be compared to the destinations above in terms of easy access and quantify. There is a thread here about Athens that will give you a very good idea.  Also, sightseeing-wise and I know it is subjective, it is not the most attractive place other than the Acropolis area and Plaka.
If you  are feeling  adventurous, I think Istanbul is worth trying maybe combined with one more traditional destination. 

I go back 40 years, the old Copacabana Palace, and Air France , Concorde (!). It was business! Around the hotel gay area, dance bars,  picked really sexy guys. Then later there was Sauna Leblon, again packed, sex on hand, you walked into the dark room and someone would just put my cock in his ass. Rooms with rows of beds with people fucking, and so on! Pre HIV. Of course I was young then, distant memories.

Never been to Naples other than in the train station in my way to Amalfi. From friends, I understand that pre covid there was a cinema, Argos or something like that,  very similar to the Kosmos in Athens (easy accessible and cheap gay4pay fun). The cinema closed during covid and never reopened. Apparently there is another cinema near the train station but it is nowhere near as good. Rent-wise on Hunqz, there is some African talent but it is quite challenging and you need to exercise caution. 

Never been to Naples other than in the train station in my way to Amalfi. From friends, I understand that pre covid there was a cinema, Argos or something like that,  very similar to the Kosmos in Athens (easy accessible and cheap gay4pay fun). The cinema closed during covid and never reopened. Apparently there is another cinema near the train station but it is nowhere near as good. Rent-wise on Hunqz, there is some African talent but it is quite challenging and you need to exercise caution. 

Axel 2: behind the 4.3 stars reviews, there r a lot of off-putting reports; especially about AC, thin walls and brkfst.

Absolutely correct!
I think the Axels rest on their reputation as the most famous ("infamous"?) gay hotels in Barcelona. There's nothing special about them other than the fact they're cruisy and friendly inside and out, especially at the pool, spa, sauna or jacuzzi. 
A stay at an Axel hotel probably works best for those visitors who are too shy or afraid to venture very often to other parts of the city -- or even other parts of the Eixample.

As a frequent visitor to Barcelona for more than 15 years, in my experience no hotel of any decent size will care if you are having visitors or not. Catalans make a point of those things not being their business. While I agree both hotels are very handy for "meetings", at times, Axel and Axel2 charge ridiculous rate for what they are so I would not be worried about bringing people over at other places.

It's important to remember that there are two principal sections of the Eixample neighborhood. 
Thermas is at the southern edge of what's called the "left" section: the "gayborhood" of Barcelona.
So to be really close, you want L'Esquerra de l’Eixample (Catalan meaning "left"). More specifically, the blocks in which Thermas is located is La Nova Esquerra de l'Eixample (Catalan meaning "new left"). 
The other part of the Eixample is the "right" section. La Dreta de l'Eixample ("right") is pretty big, with hotels that can be very far from your gay destinations.
But as long as your hotel is close to the Metro L1 line, however, even the right section won't be a problem. As @jensplatta said, the Rocafort station is on Metro L1 and is just around the corner from Thermas. Ride-share services will also take you to Thermas.

PART TWO:
BARS: Test Me and Sammi’s both have middle eastern hustlers for sex. You can find their addresses online. Most of the guys that come to the gay bars for paid sex also come to Victoria Park. As a result, what might cost you 75-150 euro as take away from a bar will be 30-50 euro at the park. It is worth a visit, though, just to support these businesses that cater to us gays. 

THEATRES/BOOK STORES: There are three theatres and four books stores that I visited where you can find their addresses yourself online. They rarely have guys available for paid sex, but mostly for free sex with other gays. When they did have hustlers, but their number usually ranged from none to 2 or 3. The Athinaikon is the one most often listed, but I usually considered it a waste of my time because men rarely went there to find the paid sex. This is because everyone in Athens knows where to go for the paid sex in a theatre: Kosmopolit Cinema (Marikas Kotopouli). The theatre is located right next to and north of the Hotel Cosmopolit, which is itself just one block north of Omonia Square. It is the red X on the map. When you walk in, be sure to keep your ticket as you can re-enter one more time. I regularly had sex, went for a coffee, and then returned for some more sex. You will see guys in the park area in front of the hotel and theatre who are very eager for your take-away business as well. The guys will come and go into the theatre every few minutes. Once you get into the theatre, you will be hounded by guys in the back standing area even before you can have a seat. Find a seat and let your eyes get adjusted to the darkness. When you are ready, then its time to venture into the balcony or basement for the adventure. I would start with the balcony which can be accessed by the stairs to the left or right as you came into the entrance. That upper balcony area is where the young men will show their dicks and offer themselves. They will sit along the long side balcony aisles, as well as the main balcony. This is where you can negotiate to give them a blow job. However, the funky sex occurs in the basement. You should know… next to the theatres in the Philippines, I found this theatre to be one of the dirtiest and seediest places I have ever had sex. It is not, as they say, for the faint of heart! Thus, I loved it just because of the adventure! The basement area is accessed by steps on your right as you entered the main theatre section. It is a narrow set of steps that takes you down to this small open area where all the guys are smoking (and I mean LOTS of smoking!). They will check you out as you come down the steps and will quickly want to offer their services. Just walk around there to get your feel for the place. It has four bathroom stalls for blow job areas, a back area where it shows gay sex on a very small tv and has but six seats, a dark area off of that, and then two rooms where you can have more active sex. I usually sit myself down in one of those seats and start watching the movie and boys who are all now standing around trying to get my attention. If I like a guy, I then usually motion him to go with me into one of the two rooms where we can talk. The rooms have locks on them. I then negotiate for sex and compensation. I have seen/heard threesomes, twosomes, spanking, heavy pounding of anal sex, kissing, etc. come from those two rooms as I watch the gay porn. The only problem I have found is that guys will usually fake cumming (unless you say you only give a blow job) and say they will kiss with tongue and suddenly they will NOT once you start the sex. Those two rooms are the only real place there to have sex beyond a blow job. I should mention the rooms are nasty and rarely get cleaned. I would say there are three groups of guys at this place: Class A guys that are straight, immaculate, showered, would never take drugs, never smoke, and sexy as fuck. They come only to get one client for money so they can go out with their girlfriend later. They will let you suck them and they will fuck you. Class B guys are the ones who come for one or two clients and like to eat afterwards at a café. They are looking for long-term sugar daddies and usually operate in a pair with their friend. They will let you suck them, they will fuck you, and many kiss very well. Class Z guys are the drug addicts and you will see them also outside the theatre where they will typically turn 5-10 clients in a day for sex. They will do anything and everything if the price is right. Interestingly, most of the guys IN the theatre are from Bosnia, Romania, Albania, Macedonia, and Bulgaria. Prices here ranged from 25-50 euros depending on the deed negotiated, but they did have to pay for their ticket so I always footed another 5-10 euros to cover that. I met several of the class A guys that I later brought back to my place for extended sessions. PART THREE follows…

There are plenty of hotels nearby. The closest ok hotel is probably called Villa Emilia - 150 metres but speedo1 was right anything in Eixample neighbourhood should be very walkable (such as Casanova 10, again Ok,  or if it Is your cup of tea Axel Hotel but plenty of options with ample price range available - more on the boutique side).  Hotels near Plaza de Espana such as the intercontinental are probably 15 minutes walk away while hotels in Gracia and Las Ramblas are 20 or 25 minutes walk away. Taxis in Barcelona are very cheap. You can use FreeNow or hail them in the street which I always do (safe and easy).  For instance a taxi from the Hilton (Las Corts)  which is not very close is less than 10 euro while a ride from Gracia is 6 to 7 euro (Curio Alexandra or Mandarin Oriental).
If you want to use public transport, there is a metro station 150 metres away - Rocafort on Line 1.
Due to the relatively central/easy to get to location, I honestly would not chose a hotel just on proximity to Thermas except that I intend to invite one of the guys to the hotel room.
In terms of recommendation, It would be handy to know if you have loyalty with any hotel chain or price range. 

I was with a bit of flu so I did not make it to any of the bars in the end. Hired a guy I had  met before through Hunqz, skinny and very very hung (100E with cum and full service) and oddly he asked to meet in an hotel by the hour outside town as I could not host (I was with friends who were staying in the same hotel). A proper love hotel, 27 euro an euro.  Not as good as the first time but I was not in an exploratory mood.  Went also to the cinema near kotsia square, had a few quick encounters - 20 to 40 euro. Can't complaint for the price!. Picked up two guys from Omonia and they were a write-off both of them. 
Back in early January after a few days in Istanbul so hope to make it to the bars.  Thanks for the advice. 

I was with a bit of flu so I did not make it to any of the bars in the end. Hired a guy I had  met before through Hunqz, skinny and very very hung (100E with cum and full service) and oddly he asked to meet in an hotel by the hour outside town as I could not host (I was with friends who were staying in the same hotel). A proper love hotel, 27 euro an euro.  Not as good as the first time but I was not in an exploratory mood.  Went also to the cinema near kotsia square, had a few quick encounters - 20 to 40 euro. Can't complaint for the price!. Picked up two guys from Omonia and they were a write-off both of them. 
Back in early January after a few days in Istanbul so hope to make it to the bars.  Thanks for the advice. 

There are plenty of hotels nearby. The closest ok hotel is probably called Villa Emilia - 150 metres but speedo1 was right anything in Eixample neighbourhood should be very walkable (such as Casanova 10, again Ok,  or if it Is your cup of tea Axel Hotel but plenty of options with ample price range available - more on the boutique side).  Hotels near Plaza de Espana such as the intercontinental are probably 15 minutes walk away while hotels in Gracia and Las Ramblas are 20 or 25 minutes walk away. Taxis in Barcelona are very cheap. You can use FreeNow or hail them in the street which I always do (safe and easy).  For instance a taxi from the Hilton (Las Corts)  which is not very close is less than 10 euro while a ride from Gracia is 6 to 7 euro (Curio Alexandra or Mandarin Oriental).
If you want to use public transport, there is a metro station 150 metres away - Rocafort on Line 1.
Due to the relatively central/easy to get to location, I honestly would not chose a hotel just on proximity to Thermas except that I intend to invite one of the guys to the hotel room.
In terms of recommendation, It would be handy to know if you have loyalty with any hotel chain or price range. 

There are plenty of hotels nearby. The closest ok hotel is probably called Villa Emilia - 150 metres but speedo1 was right anything in Eixample neighbourhood should be very walkable (such as Casanova 10, again Ok,  or if it Is your cup of tea Axel Hotel but plenty of options with ample price range available - more on the boutique side).  Hotels near Plaza de Espana such as the intercontinental are probably 15 minutes walk away while hotels in Gracia and Las Ramblas are 20 or 25 minutes walk away. Taxis in Barcelona are very cheap. You can use FreeNow or hail them in the street which I always do (safe and easy).  For instance a taxi from the Hilton (Las Corts)  which is not very close is less than 10 euro while a ride from Gracia is 6 to 7 euro (Curio Alexandra or Mandarin Oriental).
If you want to use public transport, there is a metro station 150 metres away - Rocafort on Line 1.
Due to the relatively central/easy to get to location, I honestly would not chose a hotel just on proximity to Thermas except that I intend to invite one of the guys to the hotel room.
In terms of recommendation, It would be handy to know if you have loyalty with any hotel chain or price range. 

I agree Xpaulo, Aquarius is  good for what it is. It does perfectly what it says on the tin.  It is dirty, yes. The cabins are uncomfortable, yes. In relation to value, you need to be firm that no way you  are willing to pay more than 2000TLR (65 euro). There should be more than happy with that for a full service. They always quote 100 USD to start with but no way. I was there last week myself after Athens but only for a couple of days over the weekend. 
I did notice this time that there were less "professionals". The pool over the summer was better.

Any update on Athens heading there next week after one year.  I miss the old kosmo, some very good finds. The new cinema near kotsia is nowhere near as good and dead by 7pm. Never had much luck in any of the parks. Victoria is full of eye candy (if you are into Arab guys) but they are all in groups chatting so difficult to approach etc.  Omonia is very dodgy.