Silverlink North London Line:
|Terminates here||Richmond||Kew Gardens||east|
The toilets by the District Line platforms are closed by 23:00. There is a gentlemen's toilet on platforms 2/3 which is open past 23:00, however, it is not the most pleasant of experiences. The toilet was flooded last time I was there. If you're not desperate, I would consider waiting till you get home.