The only sinkhole in Buda in good condition is not far from the green triangle trail. It was cleaned out by a team of scout rock climbers in 1988. This geological formation is in a protected area. It is six metres deep and it is not fully enclosed, so approach with extreme caution.
One can only climb in and out with the help of rock-climbing equipment. If you are trapped down there, you will not be able to leave without the help of a team of climbers
A few pictures of the sinkhole: