One of the benefits of living in one of the most multicultural cities in the world is that we have a rich array of cultural sites to visit. One of the most interesting of which is the BAPS Shri Swaminarayan Mandir London, listed in the Guiness Book of Records 2000 as the "Biggest Hindu Temple outside India", the Temple, in Neasden, was built by His Holiness Pramukh Swami Maharaj, and is made of 2,828 tonnes of Bulgarian limestone and 2,000 tonnes of Italian marble, at a cost of £12 million.
The website makes it clear that "everyone is welcome to visit the BAPS Shri Swaminarayan Mandir. Individuals and families do not need to book their visit. On arrival, please enquire at the reception desk if a guide is available.", and has an excellent page on how to get there.
The Temple's Website is at http://www.mandir.org/
It's situated at 105-119 Brentfield Rd, North London, NW10 8LD (Nearest Tube Neasden), click here for a map.