Despite its size, Singapore is perfectly situated to blend in with other destinations in Southeast Asia. Some recommendations include:
Singapore and Malaysia: Add an extension to Kuala Lumpur or the paradise islands of Langkawi for a cultural and beach experience.
Singapore and Indonesia: Combine the modernity of Singapore with the natural beauty of Bali or the Gili Islands.
Singapore and Thailand: If you want a combination of luxury and tradition, a trip to Bangkok or Phuket can perfectly complement your visit to Singapore.