There's another on Dual Sight in bomb site 2. You need 2 people and some time
Get Person 1 to jump on the boxes right in front of the ramp (looking toward the showers). Person 2 crouches in front the of the white generator (the tunnel up to 1 is directly to the right), and Person 1 jumps on their head onto the white generator. Person 2 then crouches in front of the tall boxes in front of the small box that Person 1 was standing on originally (tall black boxes), and Person 2 jumps on their head onto the boxes. Run to just the right spot near the edge of the bomb site, and it will let you set on the box, preventing anyone from defusing.
It's really hard to do though, especially if you mess up or get found before you finish.