It's not a Silicon Valley thing. There are tech scenes in the smallest of places, you just need to pay attention. The UK is brimming with tech scenes, especially London.
What counts as a 'tech scene', out of interest? I'm based in London, and don't really have any friends that are programmers, or really see much going on.
One place to look is "users groups" for whatever tools you use. So if you were in Amsterdam and you work primarily in C++ you could look up "dutch c++ users group" and come up with this: http://www.meetup.com/The-Dutch-Cpp-Group/
Another good bet is to spend a month in a coworking space. There will be events sometimes. At the friendlier ones people go to lunch together. Different spaces are different though. Some everyone kind of sticks to themselves.
You can volunteer at RailsBridge or other nonprofits. There are also "hacker spaces" that you can just hang out in and work on a project.
You can also look up conferences that are coming through your city and go to them. Many people will be from out of town, but you'll meet a few local people there too.
Search on meetup.com for a topic you are interested in, there are loads of tech meetups in London (usually with beer and food provided) and it's easy to get chatting to people so I wouldn't worry if you are going to one on your own.
A couple I would recommend are the React meet up, usually held at Facebook's office, and Functional Programming for the Web, both run by an agency (I think?) called Red Badger - but obviously that depends on what your interests are!
Thanks, I will have a look. Mostly Go and Python at the moment, so I'm sure there are some decent meetups in London somewhere. I'm Clapham based.
Have you got any experience in London with meetups for people looking for work? I will need to hire at least 2 more devs this year for my startup and have no clue where to start. Certainly don't want to use a recruiter...
Somewhere I can get involved?