Escolta Street is worth a visit if you're keen to look at what Manila used to be. Back in the fifties and even sixties, this place was filled with businesses and commerce. However, now there are many dilapidated buildings, trash on the streets, and many, if not most, businesses have vacated.
However, it makes it all the more interesting now. There's a small revival happening through weekend markets and such. Try visiting the Escolta Saturday Market (which happens once a month), visit 98B COLLABoratory, or take walking tour via Viva Manila. There are also a few art galleries situated in the area.
There are also some amazingly beautiful old buildings in the area. If you're into architecture, it's worth a visit. read more