Unconventional ways to meet people

Here are some funny ways to meet random people in Spain. It is mainly to practise Spanish, but occasionally they become long-term friends.
Wallpop: The first words I learned in Spain were "Este es disponible?". I am a fan of buying and repairing. Wallapop is a popular website in Spain to buy used things. I would go there and start chatting with random people about items on sale. Sometimes, I would ask for details and bargain. When I bought things, I would meet in person to chat. I have met a lot of geeks this way.
CEX/WeBuy: Webuy or CEX is another used gamer store. There you can buy a lot of good gadgets at cheap prices with a 3-5 year warranty. I have bought most of my used electronics from that store.
Cabify: I love to use cabs when I can afford them. When they see my name, they often try to figure out where I am from. I turn it into a game by saying "Adivinate". No one has yet been able to guess that I am from India. I have had a long range of conversations and even visited restaurants they recommended. There was once this guy who was an air steward on a private plane in Turkey. We talked about culture, life with a varied sleep schedule, and his dream of becoming a pilot.
Jubilad@s: I live in an old people's barrio now. It is quite fun. It is far off from the city. The bus service can be spotty. Oftentimes, I have to wait 15-20 minutes between buses. It was then, that I realised that instead of just looking for pigeons, I could just talk to the elegant people around me. It is so much fun. Once, I had a long conversation with this lady who was 83 years old. She told me the history of this area. How she has seen people move out slowly and that she had seen the king hunting near the forest when she was a kid. I asked her, that these stories should go in her autobiography. She chuckled and I got on my bus.
Airport: In the recent movie, "The real pain", Benji, played by Kieran Culkin, has a fascination for airports and people you meet there. I could relate to him. Airports are Augian Non-Places. People just pass, but I try not to be that person. Oftentimes, I have made long connections with people I met at airports (not in Spain but flying to). I met a woman once on a flight to Vienna. She is the mother of a news presenter. We had long talks about Cuba, Castro, and India. Recently, I met a Spaniard at the Delhi Airport, who had a very bad time in India. We talked for several hours about cultures, his travels, and his passion. He is an industrial designer and I am meeting him soon in BCN.
Clothing shops: Now this is a bit cheesy. I am very picky with clothes. Until recently, I got most of my clothes stitched and wore them down to their last thread. Now, I can't do that in Spain due to costs and processes. But, when I go to a clothes store, I try to ask them as many questions as I can and for their recommendations. The funny thing, I learned is that many of these people are fashion designers or stylists. You must pick stores carefully. If you go to the centre, they won't have any time to assist you. Go to slightly residential ones, like near the Rio.
Mercadona : Not all supermarktes, just Mercadona. There staff here is absolute best. You can go with questions about ingredients and practise your Spanish with them. Do not take much of their time. You can ask questions about discounts, make jokes, and ask them ingredients.
Public Offices/Hospitals : This is an obvious, but if you go to an public hospital or office, you must speak in Spanish. You can have longer chats by asking more about procedures or explaining things. In these places, it is better to write things before hand so you keep things formal and dont call them by the wrong pronoun.
Delivery Pickup: I often do not get things delivered to my place, unless I am ordering lumber. I pick them at "tabacs" or "loterías" around the city. Every time I go there I meet a new person. The lotteries are pretty interesting places. You can buy a lottery too and ask them questions about the lotteries won in the place. These places are slowly changing now. But on the edges of the city, there still is a place, where cheerful people run these places.
Bar Paco/Ahmed/Rodilla: The last but not the least. There is a bar at (almost) every corner in Madrid. I go to the ones near my house to sit and have tea. The trick is the frequency. You must be frequent. Otherwise, the conversations with the owners don't happen. There is this particular bar in Lavapies, where I used to go often. The owner is a Bangladeshi and he makes the absolute best lentils. I used to take lunch there. Then, I moved out of the neighbourhood. I still go there and he does recognise me and asks me about things. We talk in el broken español.

What are your places?
Cheers