It‘s inside of flood control dam #3, but every time I go in there.echoechoecho
Yes you can, but it will cost a pretty penny.
I'd use a squid. It would detect the platinum quickly. If its worth getting you can pay the money to use a squid based sensor SQIUD super conducuting quantum interference device. It detects deformations to the earths magnetic field made by conductors. copper cold etc very sensitive 10^12 times more sensitive than a compass.
