Ariyalur is noted for its cement industries and has huge reserves of lignite. Gangaikonda Cholapuram built by the King Rajendra Cholan of Chola Empire, an UNESCO World Heritage site is situated in the district. This district is also known for its rich prehistoric fossils. Many fossils of gigantic Molluscs, Jawed fishes were discovered here. Notably, The Rajasaurus, an Indian dinosaur genus was identified here.