The Temple of Apollo Epicurius is considered one of the most important ancient temples in Greece, designed by the same person that designed Parthenon, Iktinos.
The temple is covered by a special tent that will remain for many years, not only until the preservation works will end but maybe for ever, in order to protect this important monument.
Unfortunately, the restoration process has been stopped the last couple of years due to the lack of funds. It is sad to realize that such a monument depends on funds, considering that its stability is in danger… However it seems that within 2017, there will be some more money coming and the restoration process will start again.
More historical info: https://en.wikipedia.org/wiki/Bassae