Kuala Terengganu, KT in short, is located at the east coast of the Peninsula Malaysia and at the mouth of the Sungai Terengganu (or Terengganu River) that empties here into the South China Sea. It is the capital of the state of Terengganu, which forms, together with Kedah and Kelatan, the heartland of Malay culture. KT is a good stop for one or 2 days before moving on along the east coast or towards the National Park / Tasik Kenyir.
Langkawi is an archipelago of 99 islands in the Andaman Sea, some 30 km off the mainland coast of northwestern Malaysia. The islands are a part of Malaysia’s Kedah state, but are adjacent to the Thai border. By far the largest of the islands is the eponymous Pulau Langkawi with a population of about 45,000. The island is a declared duty-free zone.
The peak season is from December to March when moonson at the eastcoast shuts down most of the Islands there (Perhentian etc.). This makes Langkawi a good island alternative during that time period. Generally though, Langkawi can be visited all year around.