Merneptah (or Merenptah if you prefer) was the 13th son of Rameses II and would become the 4th Pharaoh of the 19th dynasty upon the death of his father.
A number of mortuary temples of the 18th and 19th dynasties are tourist attractions today on the West Bank of Luxor. They are in a varied state of restoration and Merneptah's own temple is in a very poor condition when compared to that of Hatshepsut (Deir el Bahri) and Ramses III (Medinet Habu). Many of the finds from the mortuary temple of Merneptah were actually re-used material from temples of previous 18th dynasty Pharaohs. These include Amenhotep III, Akhenaton and Hatshepsut.
An article on the mortuary temple of Merneptah can be seen on Osirisnet.net.
Dr. Karl Leser's website (Maat-Ka-Ra Hatschepsut) provides a photo of a limestone block fragment featuring 2 cryptograms of Hatshepsut's throne name. In total he mentions 10 blocks in total from Merneptah's temple. Please follow the link, go to Monuments>Other Monuments>Fragments for further details.