evidence: The eastern seaboard of Borneo was charted, though not settled, by the Portuguese in the early 16th century. The area of Sarawak was known to Portuguese cartographers as Cerava, and by the early 19th century, Sarawak had become a loosely governed territory under the control of the Brunei Sultanate. [...] The State is separated from Peninsular Malaysia by the South China Sea -- a distance of 600 kilometres. It is directly joined to the State of Sabah to the northeast where the Sultanate of Brunei forms a double enclave. Inland, Sarawak borders with Kalimantan, Indonesia. [...] Humidity is consistently high in the lowlands ranging from 80 per cent to 90 per cent.