mar·tyr·i·um 
(mär-tîrē-əm)
(mär-tîrē-əm)n. pl. mar·tyr·i·a (-ē-ə)
A church or other edifice built at a site, especially a tomb, associated with a Christian martyr or saint.
[Medieval Latin, from Greek marturion, from martus, martur-, martyr.]