The romance in a lakorn usually takes place in an island or the beach, or is contains a juicy part there. N'ek gets kidnapped there, p'ek and n'ek run away there, one of the pra'nang get shipwrecked or stranded there, they get trapped there, etc.
Some examples:
Ruk Nee Hua Jai Rao Jong - N'ek and p'ek get stranded there which creates the good memories and growing of romance.
Jum Luey Ruk - P'ek kidnaps n'ek falls for her, rapes her, creates good memories for future flashbacks.
Manee Yard Fah - N'ek gets saved by p'ek and they end up getting stuck on the island. Yet again creates good memories and factor for the pra'nang to develop feelings for each other.
Sawan Being - Rape, creates baby, p'ek fall for n'ek.
Ngao Kammathep - Pra'nang gets imprisoned on the island. Gets stuck there. Creates good memories.
Duang Jai Patiharn - P'ek kidnaps n'ek there, realizes feelings for each other.