TL;DR - GRUB goes from strength to strength. A new venue, but greater than ever.
First thing's first - GRUB has moved quite a bit over the years. Some of the older reviews on here talk about different locations, but right now (September 2018) it's based at the old Mayfield train station, located in a yard at the rear which is accessed from Baring Street. It's certainly off the beaten track, but it's not far at all from Piccadilly train station, and once you're on Baring Street it's hard to miss.
Basically you've got a big yard with food and drink retailers based in converted shipping containers all around the edge, and then a large seating area in the centre. We've come here many times and everything we've eaten has been fantastic, but the real treat is that the traders change on a frequent basis so there's always something new to try.
There's also a big bar serving lots of different craft beers, many of which are local. I also love the fact that the bar and most of the retailers accept contactless payments so there's little need to carry cash.
The crowd which comes here is pretty mixed - generally young, but also older folks and families, and dogs are welcome too (it is outside, after all!). It's a really nice and chilled crowd, everyone getting along and enjoying their food and drink. Definitely worth a visit, even if it is a little hard to find the first time.
Oh - and check out there website and social media! Although the main venue is open on Friday and Saturday only, they also run a vegan food fair on Sunday but sometimes the venue is Fairfield Social Club rather than Mayfair! read more