The route for people queuing to see the Queen lying in state at Westminster Hall in Parliament has been released by the government.
The line will start at Albert Embankment near Lambeth Bridge, and could stretch all the way to Southwark Park in south-east London.
Those queuing are asked not to attempt to save a place for someone else, or leave personal items unattended, or put up tents.
Once people reach the front of the queue, they will have to go through airport-style security before entering Parliament.
Get more details here.