Central Mosque, where we watched an imam leading prayers, and St Martin's Church (see image and here), where we ate in the cafe and I meditated in a side chapel. On the street, I heard a Christian preacher and received a free Koran from a Muslim propagandist - but, when I sat on a bench to read it, a passerby advised me to read the Bible! Like Poul and Karen Anderson's King of Ys Tetralogy, these are books in which God(s) are active. In fact, here is a centuries-spanning scriptural sequence:
a Torah scroll in a synagogue;
a Bible on an eagle lectern in a church;
a Koran in a mosque;
a Granth at the highest point of a Gurdwara.
And what a seemingly endless historical succession: the Granth includes hymns written by Muslims who accepted the Koran which repeats stories from the Bible which incorporates the Torah which is the only scripture accepted by Samaritans. Other hymns in the Granth were written by Hindus who accepted the Veda and its many sequels. These are the works of millennia, not of any single author or even of a husband-wife team... Nevertheless, the Andersons present an impressive four-volume account of changes among Europeans and their Gods.
If I were able to visit Ys, both backwards and sideways in time, I would:
visit the various Temples and Shrines;
ask whether it was permissible to meditate in one of them;
in any case, meditate in lodgings in Old Town or high in one of the towers surrounded by seagulls.