Day 4: Today, you'll visit one of the smallest towns in Australia to retain its own postcode. Cooladdi, taking its name from an Aboriginal term for u201cblack ducku201d, was once home to 270 residents. Now only four remain. Call into the only business in town, the Fox Trap, a pub, post office, restaurant, motel and service station rolled into one!n On arrival in Quilpie, make your first stop at the Visitor Information Centre, Museum and Gallery. Relax in air-conditioned comfort and access the free WI-FI. Quilpie is home to the exquisite Boulder Opal. The whole family can have a go at uncovering this pretty gemstone at a free fossicking site just two kilometres west of Quilpie. Late this afternoon, drive approximately 7.4 kilometres from Quilpie to take in a spectacular sunset from Baldy Top, a magnificent boulder formation, millions of years old. The relatively easy ten-minute climb to the top will reward you with breathtaking panoramic vistas, the perfect sunset photo stop.