Shield Shop

The Dark World Shield Shop can be found directly west of the Pyramid, and east of the Village of Outcasts, in A Link to the Past. This shop is completely fenced in, with it's only access point along the Northern perimeter. Link must jump a series of fences to even get in.

GBA version
In the Game Boy Advance version, the Dark World Shield Shop sells nothing except for shields. The abundance of Like Likes surrounding his shop may be advantageous for this particular business.

The fox-like Shopkeeper won't sell Link any shield inferior to the one equipped.