When I after that press the green button, the door opens and I can climb in.
After a few steps I find my backpack in a niche at the right side.
I am curious to see what there is further on, but I only find a warning sign, warning for fall.
Evidently it is the way out to the Thames.
As I don't want to go there, I turn around and make my way back to the security gate.
I am sure I have to spend a lot of time finding my way down here in the sewers so I have better start drawing a map.
In my backpack I find a key to the sewer doors.
Now I can reach all parts of the sewers.
It takes me quite a while to walk around and draw my map but I think it's worth it.
I can now decide exactly how to go and don't have to wander at haphazard.
To the right you can see my map.
When I was walking about I found a couple of locked boxes that I couldn't open and
a brick wall that differs from the other walls.
Perhaps it hides something interesting, but that has to wait for the time being.
I also found a grate leading to a small courtyard.
There are some buildings that I think are important to visit, but from the sewers I can only reach Old Hospital Block and Deveraux Tower.
When I look at my sewer map I see that Old Hospital Block is the nearest one, so I'll start with that one.
Helped by my sewer map I find my way to the exit. After climbing the steps, I find myself in a small room with a flight of stairs and a door without fire alarm. It doesn' look dangerous so I dare open it and enter.
I look at my GPS to decide my position and now I can rightly place Old Hospital block on my map showing the Tower grounds.