Before becoming an Umayyad Caliph, Abd al-Malik initiated a settlement at Ramla in 712. Shortly thereafter, he commissioned the construction of Jami' al-Abyad, or the White Mosque; however it wasn't completed until the reign of the succeeding caliph, Umar. Subsequently, during one of many turbulent occupations that resulted in damages to the mosque, it was reconstructed in 1268 by the Mamluk ruler Baybars.
Much of the mosque was constructed in white marble with cypress and cedar wood used for the doors. With its four facades organized on a cardinal axis, it measured approximately 93 x 84 meters. One entered the mosque from a gate on the eastern facade, which is currently in a state of disrepair. The still present minaret is to the north of the structure, square in shape with five stories highlighted each adorned with window niches and with a balcony towards the top. Probably influenced by Crusader design, it was constructed by the Sultan al-Nasir Muhammad in 1318, however there is some speculation that the minaret may have earlier been located closer to the center of the mosque as remnants of a square foundation have been found there. This may have, however, been just a fountain. The mosque also featured three underground cisterns with barrel-vaulted aisles below the central court.
While it is likely that the White Mosque possessed a prominent location in the Umayyad settlement, today it is situated to the west of the central thoroughfare in the old quarters of the city. Yet, it is still maintains significance as it contains the shrine of a famous Palestinian saint Nabi Salih at its northwestern-most section. The original dome-covered shrine has been exchanged for a concrete building with a leveled roof.
Sources:
Prag, Kay. Israel & the Palestinian Territories Blue Guide, 315-322. London: A & C Publishers Limited, 2002.