Quakers that like to rocket/grenade jump will like the
area around the respawn. You can boost yourself up there
and camp above the respawn and walk around the roof of the building.
As being a sniper myself, I tried to make areas that I would like
to snipe in. There are two dark towers on the sides of each base and
a larger tower in the front, as well as catwalks around various parts
of the level.
The water is a little difficult to get out of. I find that it is a
little funny to blast someone into the water who doesn't know how to get
out. However, u can RJ or Gren jump out.
There are two ramps coming down into the sewers just behind the respawn
areas. The ramp paths intersect and follow a series of ramps to a water
cave. The demoman can blow the wall that is fairly noticable. Under the
island in the middle is an underwater tunnel that can take you under.
The diamonds are located in a small bunker at the very back of each
base, as to provide a challenge to get to it. Once retreived, return to
the very back of your base where you will see a portal. Jump through and
you will earn your team an extra ten points.