Death traps are a combination of pathing, traps and buildings to buff monsters before they reach the defenseless target. Anything can be protected by a death trap, which can produce humorous results like "Space death trap" where a space is protected and "block death buff" where a block is destroyed.
Useful and common types
Silo Death Trap/Resource Pod Death Trap
More well known by it's abbrevation SDT, a Storage Silo or Resource Pod is protected in such a death trap. Usually, a Town Hall Death Trap is put inside the silo death trap, as both silos and town halls give loot when destroyed. Using silo death traps makes making towers uncatapultable harder.
Town Hall Death Trap
Town Hall Death Traps are usually inside SDTs and is a part of them. The Town Hall is also made to be the last building to be destroyed by enemy monsters.