Why go
The topography explains why places that look close on a map can belong to very different landscapes. Compare the Tonlé Sap basin with the Dângrêk cliff line near the Thai border, the Cardamom ranges toward the coast, and the higher ground of Mondulkiri and Ratanakiri.
The full story
The Tonlé Sap basin and Mekong lowlands form Cambodia's broad, low core. Around the lake, much of the ground lies below 100 metres, with more rolling terrain as it rises away from the basin. The Dângrêk Mountains form a long northern rim; their south-facing escarpment rises abruptly above the plain near the Thai border. In the southwest, the Cardamom Mountains run roughly northwest to southeast. Phnom Aural, at about 1,813 metres, is the country's highest peak. The Elephant Mountains extend south and southeast from that upland system, leaving a narrow coastal lowland beside the Gulf of Thailand. Across the Mekong, the northeast rises into plateaus and hills that continue toward the highlands of southern Vietnam. These are useful contrasts when reading a route: a lake-basin journey stays largely on low ground, while the northern and southwestern margins bring steep slopes and passes into view. The mountain belts also help explain why the coast and interior have historically had different connections.