Agra, India
The roadway to the fort has a sharp bend at the end and the entrance doors have giant spikes on them. In the event of elephant attack the elephant would not be able to get up lots of speed on the run-up and I believe for whatever reason elephants have an aversion to giant spikes... I forget why.
The guide told us there were two motes surrounding the Agra fort. The first was of crocodile infested water. The second was a pit of lions - since getting back I ...