La Garita is an odd little town full of character and with its own large, dark volcanic sandy beach. Be sure to check what the tide is doing as when there's a high tide it's often too rough to do much swimming, as is the case with most of the beaches in the north that aren't protected by any kind of breakwater.
There is a public bus service to get you there but it's not great so a hire car is recommended. The town (village?) itself has everything you could need. Close to the beach are a handful of cafes, tapas bars and even a restaurant almost on the beach itself. There supermarkets, cash points ..... all withing a five or ten minute stroll from the beach.
The beach itself is quiet. No sunbeds or services provided though there are some trees and bushes which help provide natural shade. A lof of the beaches in the area are popular with surfers but not this one (too many rocks I guess) so that helps make it even quieter.
La Garita village is worth a walk around. It's modern mixed in the with the old. Obviously an influx of money was made available over the last ten years or so and a lot of work went in to make everything more accessable and someone with some very bad taste built a town square. Modern houses and apartment blocks went up next to some very shabby looking buildings the obviously nobody cares about any more.
This is one of those beaches I'd recommend for a visit if you're here for a few months but if you're here on holiday, in the area then head to Playa Melenara instead.