
Bandar Seri Begawan, also known as BSB or just Bandar, is the capital of Brunei. It is probably where you'll spend most of your time and money. You'll probably just refer to the city and its suburbs as simply Brunei or Brunei City, since the country is so small.
You can see most of BSB's sights in a day. One of the most impressive things in the whole country is the Omar Saifuddin Mosque. At night it's particularly stunning with green lights illuminating the dome, casting a pleasant reflection in the pool below. It's the first religious institution I've ever seen with an escalator!
Something not to miss if you like all that is gold and glittering is the free Royal Regalia Building, a museum of the sultan's treasures. You can see the sultan's coronation regalia as well as a myriad of gifts presented to His Majesty by various heads of state.
If you are interested in seeing a water village, take a river taxi to Kampung Ayer, where you can walk around on wooden planks that connect some of the houses.
Amongst backpacker crowds, the Jerudong Playground was once one of Brunei's major (if not only) attraction because it was like a free Disneyland. However, they began charging admission in March 2000 and since the amusement park is located in a suburb, you will have to take an expensive taxi back to your hotel. If you are staying at the Pusat Belia, you may be able to hook up with their pre-paid tour.