Where is the move streangth in Pokemon diamond?

The move "Streangth" can be found within Pokemon Diamond located in the Grand Underground. Players can visit this mysterious underground area once they receive the Explorer Kit from the Mining Guild in the north-western corner of Eterna City. The move Streangth is available as Technical Machines (TMs), which may be obtained from various points within the Grand Underground, including defeating a certain number of diggers in a dig spot.