Our first destination was Gunung (Mountain) Mulu National Park in the Malaysian state of Sarawak and tucked in behind the tiny nation of Brunei Darrusalam.
There is no road into Mulu; the only access is by air.

The national park, c. 53,000 ha in extent, is a UNESCO World Heritage Site notable in particular for its karsts with extensive caves and caverns, and pristine rainforest.
Gunung Mulu is 2,376 m high, and the national park headquarters where we stayed (in luxury!) are just 40 m above sea level, so the Park contains a remarkable range of environments.
However, upland areas are only accessible on guided treks suitable for those considerably younger and fitter than I.

This is wet country (possibly the wettest spot we visited in Borneo), with a mean annual rainfall at the park headquarters of about 4,500 mm (180 in).
I shudder to think how wet it is higher on the mountainside. True to form, we experienced several torrential downpours in the 4 days we were there.