North Lombok in details:

Bangsal, or the port of Bangsal is a hassle and public transport north from here is infrequent. Several minibuses a day go from Mandalika terminal in Bertais (Mataram) to Bayan, but you will have to get connections in Pemenang and/or Anyar, which can be difficult to navigate. Simplify things and get your own car rental is the best way.

Sira, is the name of peninsula that has an insanely gorgeous, sweeping white-sand beach, some snorkeling offshore where the reef is under recovery.

Gondang and around. Just northeast of Gondang village, a 6km trail heads inland to Air Terjun Tiu Pupas, a 30m waterfall that is only worth seeing in the wet season. Trails continue from here to other wet-season waterfalls including Air Terjun Gangga, the most beautiful of all. A guide is usefull to navigate the confusing trails in these parts.  Don’t worry, we can help you.

Bayan, is the place where Lombok’s animist-tinted for of Islam called Wektu Telu was born in humble thatched mosque nestled in these Rinjani foothills. The best example is Masjid Kuno Bayan Beleq, next to the village of Baleq, built in 1634. This is the oldest Masjid in Lombok ever built.

Source: Lonely Planet Bali and Lombok