St. Andral's Church

What we know

Church in Vallaki with hallowed grounds protecting congregants from vampires and undead (Session 4 @ 01:02:36)
Ismark Kolyanovich asked party to escort Ireena Kolyana here (Session 4 @ 01:02:36)
Centuries-old stone church; Morning Lord sunburst altar; graveyard with iron fence (Session 9 @ 00:28:49)
Dr. Rudolph van Richten substituting for missing Father Lucian Petrovich (Session 9 @ 00:40:12)
Undead cannot enter church grounds; sanctuary during Wachter evacuation (Session 16 @ 01:37:20)
Three assassin corpses found outside gates after Bryce stepped out—Bryce then missing (Session 16 @ 01:39:29)
Church crypt accessed via rug trapdoor and key necklace near altar (Session 17 @ 18:19)
Wachter family sheltered upstairs morning 8th; Nightingale maintained Bryce disguise until crypt reveal (Session 17 @ 16:22)
Father Lucian Petrovich rescued and returned; Dr. Rudolph van Richten rescued—identity confirmed to party (secret) (Session 18 @ 02:05:52)
Lucian restored church wards; Feast of Saint Andral resumes 9th (Session 18 @ 02:50:10)
Two thrall-conversion victims stabilized on church floor; reversal study underway (Session 18 @ 02:41:09)
Midnight 9th: Irredel werewolf custody—moonstone counteracted wolfsbane; Sildir arm amputated (Session 22 @ 00:58:00)
Party long-rested in church after midnight events (Session 22 @ 01:35:00)

Unconfirmed: whether refuge holds against Strahd's interest in Ireena (Session 4 @ 01:02:36)