In Lyra's universe, this church appears as 'the great square-towered oratory of St Barnabas the Chymist'. It's an unusual sort of church by English standards, looking very much as if it belongs elsewhere, probably the Mediterranean.
The old artisans' district of Jericho isn't often visited by casual tourists. The name was originally a jocular reference to an out-of-the-way place, the sort of place one might be banished to, though it's only a short distance from St Giles. It's a little further to walk though - historically town and gown were kept severely apart and only a few streets break through to the University areas.
For all its obscurity as a living district, it has been well recorded in fiction. Thomas Hardy's ambitious young stonemason Jude Fawley finds lodgings here amongst his fellow working men while he seeks in vain for the classical education he yearns for (Hardy calls the area 'Beersheba' just as he calls Oxford 'Christminster', but he would, wouldn't he). Colin Dexter sets much of one of his Inspector Morse stories, The Dead of Jericho, here, and of course in Northern Lights, Lyra and her friends come looking in the church for the missing gyptian boy Billy Costa feared kidnapped by the "gobblers", the childrens' nickname for the Church's General Oblation Board.
Jericho is no longer a working-class district. As in many English towns, the narrow streets and terrace houses which were home to craftsmen and college servants in the nineteenth century are now the sought-after abode of the liberal bourgeoisie, and as such the area is full of restaurants, bars and specialist shops, especially along Walton Street.
Behind the traditional and scholarly Oxford there has long been a quite different city, uncelebrated by the tourist guides. Oxford was an important canal port, where the Oxford Canal bringing goods from the great waterway systems of the Midlands met the Thames. The port lies behind the old artisans' quarter of Jericho, and the area still attracts water-borne folk in traditional narrowboats.
In Lyra's world, Jericho is a seasonal mooring for the gyptians - not Romany people and never spelt with an initial capital, but a breed of people who seem to speak a kind of Dutch/Italian hybrid dialect and who make their living by the waterways. Being outsiders, the gyptians are an obvious target for Lyra and her Oxford brat-pack who attack the boats and even attempt to hijack and sink one of the boats. The brats rally round, though, when one of the gyptian children goes missing, and it seems the gyptians know something about Lyra...