I have driven from Sydney to Cape York. Take 2 weeks over it and dive the reef.
I have also travelled all over South East Asia, Thailand, Koh Chang is nice, less tourists than the west coast. Cambodia, take the boat from Phnom Penn up the Tonle Sap river to Siem Reep and visit Ankor Wat.
One of the most stunning things I have done in my life. Try to go at dawn and watch the sun rise over Ankor Temple. You can also take a balloon ride. I flew out and the plane banks over the whole 100 square mile complex.
Ha Long Bay in Vietnam is beautiful, purple city, and Nah Trang beach is pretty awesome.
Ho Chi Minh City was one of the most amazingly fun city’s and Laos has some fabulous places.
For me it was the off the beaten track places that were the best, except Anchor, by far the most stunning.
A word of caution, do NOT under any circumstances walk in the fields of Cambodia and Laos!!!
Not even for a wee at the side of the road!
It is littered with un exploded ordinance/ bombs dropped by the USA in the war.
Apparently their planes shed their bombs over those countries in order to have enough fuel to get back.
More bombs dropped in one day than both side in the entire WW11.
Use Avon Skin So Soft as a mosquito repellent, the SAS use it and I did, never got bitten.