Tea lovers, take note: the Twinings flagship store in London is worth a trip. This is the place in town to find every flavor and type of Twinings teas. It's surprisingly small, but is stuffed to the gills with all sorts of tea bags, loose tea, accessories, and gifts. This is a great place to go if you want a fun souvenir of your trip to London (or if you want to take something that will be appreciated by the folks back home).
This flagship store is over 300 years old, making it the oldest tea shop in London! It's very pretty and photogenic. The employees are super helpful too, and eager to guide you towards items they think you might like.
I'm normally a loose leaf tea drinker and prefer to brew my own, but one of the coolest features at this shop is the Pick & Mix wall. You can create a personalized selection of individual tea bags (a make-your-own sampler box, if you will). Twinings has so many options, and their tea envelopes feature art that's pretty as well.
I came home with a couple of loose leaf tins as well as four boxes of their Spiced Apple and Vanilla Superblend Sleepytime Tea, which I became absolutely obsessed with on my Virgin Atlantic flight across the pond. I looked all over town for it, but I made the trek to the Twinings store because I knew they'd have it (and they did). This is THE place if you are searching for a particular or hard-to-find Twinings tea.
There's a tea sampling bar in the back, where they usually have three or four different varieties for you to try. I visited during the holiday season, so I was able to taste a couple of Christmas teas which were excellent.
The closest tube station is Temple (on the District and Circle lines). It's a short walk, but you have to go up a very steep hill so be aware.