Tangasseri or Thangassery (Thangi) is a heavily populated beach area on the shores of the Arabian Sea in Kollam city, Kerala, India.

Archaeologists recently discovered Chinese coins and other artefacts along the coast, which reveal the historic background of the location.

[5] The Infant Jesus Cathedral in Tangasseri an old Portuguese-built church, remains as a memento of Portuguese rule.

[7] Tangasseri is a picturesque seaside village with a three kilometre long beach on which stands a 144 feet tall lighthouse—a silent sentinel warning seamen since 1902 of the treacherous reefs.

The Government of Kerala was asked on the 7th January, 1959 to examine the reports submitted by the Poona Research Station and to work out comparative costs of both the schemes m the light of the recommendations made m the Reports and forward their proposal to the Government along with a statement showing the comparative costs for the two schemes These are awaited A provision of Rs 42 5 lakhs has been proposed for development works at Thangassery in the Third Plan [10]