I'm staying in Berlin today, exploring the town, meeting the foreigners and locals, spending sats and hanging out at the Bitcoin Center.

The city is not traditionally a tourist town, so there aren't a lot of hotels or guest houses around. There are a surprising number of good quality establishments though, like bars, cafes and restaurants. They're sustained by a regular stream of daytime visitors from the surrounding towns that want to cool down in the mountains, enjoy the beautiful scenery, good food and music.

Weekends especially are known to be busy, including the market, the local park and the town's main attractions, the volcano and modest water park. All of this makes Berlin appear to be a place where you could spend a week, month or even a year. There's always something good to eat, always something happening, but evenings and nights are quiet apart from the fireworks that the local youth set off.

If you do have the time, hike up the volcano or through the nearby coffee plantations. You can even book nature walks with local guides through the local Bitcoin Center.

Lightning: Berlin is a successful example of a circular economy. There are dozens of merchants that take Bitcoin. Almost every restaurant, supermarket and convenience store will accept it. People are using Bitcoin among each other, to pay bills online or to pay their suppliers from out of town. Unlike in Berlin, everywhere I went people are confident in how to process Bitcoin transactions. Every shop I approached today took BItcoin, and every Lightning payment goes through promptly.

Almost all merchants use the Blink wallet, a local custodial platform formerly known as Bitcoin Beach Wallet. There is the option to hold the value of the balance in USD, known as "stablesats," but from what I can tell, that feature is rarely used.

Some of the more prominent merchants, such as the supermarkets and restaurants, are equipped with "Bitcoinize" machines, which are stock Android point of sale devices that you can get for a relatively good price in bulk from China, at least compared to the price of a tablet or phone.

These devices also have an NFC card reader, and I do get to use my Bolt Card for the first time in a "real" life situation. However, the payment doesn't seem to go through quick enough, so the cashier cancels the invoice, gives me another one and I pay that from my Zeus wallet. Checking back with my LNbits wallet a few minutes later at the Bitcoin Center, I discover that the Bolt Card transaction indeed went through, meaning I paid twice, which isn't the end of the world, but I want to try again. I go back to the shop, but the clerk wouldn't let me make another attempt. I did however manage to use the Bolt Card at a restaurant (using the Bitcoinize machine) and at a bar (using the bar tender's personal phone). Pretty cool! But are Bolt Cards really more than just a party trick? The bar tender is definitely impressed!

In total, I visited nine local merchants today and while my payments didn't always go through Lightning fast, they always went through and everybody seemed genuinely happy to see me pay with Bitcoin.

The Bitcoin Center: The Bitcoin Center is a relatively large space where people meet, hang out, learn, exchange Bitcoins or advertise their services. There's a large room at the front where weekly meetups are held, a podcasting studio, a class room, a workshop area and a private office, around a courtyard that has yet to find its use. it makes a great impression and there are always people walking in and out, both locals and foreigners.

Inside, there's a professional ATM where you can buy and sell Bitcoin for cash. In theory. The machine does not let you buy sats with cash over the Lightning Network at all, and while it would let you sell Bitcoin for cash (requiring a phone number as identification), the machine is out of dollar bills and the withdrawal function is temporarily disabled.

There's another machine, the locally produced K1. it takes bills of small denominations and coins, although I only manage to fill it with quarters and a one dollar bill. I do discover a pretty serious bug almost immediately by chance, and the operator helps me report it to the developers.

Berlin: The town, estimated to have about 10,000 inhabitants, is much larger than Bitcoin Beach, but similarly isolated from the nearest economic center. In some ways, it does appear to be the perfect place for such an experiment. Locals are young, savvy, hard working and apart from coffee and cocoa farming, there are no local established industries. The city is dense and everything is a short walk away. The government provides few services here, and I didn't see any banks either.

The current El Salvadorian administration does not appear to be popular here, but there seems to be hope that Bitcoin can help leverage the town's advantages and provide for better living standards for people.

I'm without a doubt that as El Salvador is changing, Berlin will change too, and probably mostly for the better. But it's not clear to me that everybody will look back at this moment without regret. Digital nomads and tourists will be able to outspend locals on rent and food, which may lead to a backlash on tourism, and maybe Bitcoin.