Here's some suggestions for Sri Lankan backgrounds.
First Row: Adam's Peak - the central massif of the island, venerated by lilgrims of
all the major religions. That white at the top is a small building, sheltering an imprint in the stone, variously interpreted as the footprints of Adam, Buddha, etc.
Second Row: Koneswaram - the location of Ravana's palace in the Ramayana, now a monastery.
Rows Three-Five: Sigiriya - a palace and fortress occupied since 5th cent. BCE, with major building in the 5th cent. CE. The 5th row shows two views of the Lion's Gate, which originally had a a head made of wood and plaster, with the actual entrance through the mouth.
Sixth Row: Jetawana- Third tallest ancient brick structure in the world - a stupa with major relics. Located at Anuradhapura, which was a capitol of Lanka off and on between 5th BCE and 11th CE.
Seventh Row: Dalada Maligawa - Temple of Buddha's Tooth
Eighth Row: Sri Maha Bodhi Tree - planted in 288 BCE from a cutting from the very tree where Buddha became enlightened. The oldest living human-planted tree.
Ninth Row: in case you wanted something more generic - a Hindu Temple in Colombo.
Thumbnail
Unfortunately all the Palaces from the period covered by the mod have been so ravaged by war, looters, and time, that there's nothing worth posting for a LH background.
Personally, If I had the skill, I would create a composite of Adam's Peak and the Shiva fountain with the monkey from Koneswaram for the Ancient era, and Sigiriya with the Lion's Gate, head and all, for the Medieval. But that's a dream beyond my capabilities.