Do walking tours on Sunday a.m.

If you are visiting London or Paris, you can do self tours on Sunday mornings.  There are hardly anyone on the streets and you can enjoy the city's monuments without a crowd.  It is also great for taking pictures.  Also, during the Summer times, it will be very cool in the morning, so perfect for a walk.

Do remember that on Sundays, in London, the first trains are not usually until 7:30a.  So go for an early walk and then take the first train back to your hotel.