Bayinnaung was king of Burma from 1551 to 1581. Among other things, he unified the country, conquered the Shan States and Siam (Thailand), and made Burma the most powerful kingdom in mainland Southeast Asia. He also built a beautiful palace for himself in Bago in 1553.
The palace was renovated in 1993, and during the excavations 176 of the original teak (Tectona grandis L.) posts were dug up (image above). After 440 years in the ground, the posts were still solid; many still bore the inscription with the name of the town or minister who had donated the log to the king. This has to be some sort of a record for durability. [NOTE: I love the fact that the old posts are on display with signage at the Kanbawzathadi Golden Palace Museum in Bago. Maybe I'm not the only person that finds this sort of thing interesting].