Ilthmar is the second largest city of the Martic league, and like all the cities is a city-state. It is a republic ruled by a council elected by the various guilds and therefore consisting mainly of guildmasters.
Ilthmar sits on several islands in the river, and the banks on either side are low and swampy. While this makes the city very defensible, it also makes it damp and prone to clinging fogs. Citizens of its larger southern neighbour, Lacramar refer to Ilthmar slightingly as "the city of bogs, fogs and frogs".
Ilthmar is largely built of grey stone quarried in the low range of hills to the south. The buildings are mainly 3 or 4 stories high, the lower floors having few windows or windows with heavy, tightly locking shutters, which enable the buildings to ride out the occasional floods. It also helps at night. Ilthmar's city watch is small, and patrols mostly during the day to keep order in the harbour and markets. At night the city is only patrolled by citizen's patrols or hired bravoes who are as likely to drown potential criminals in the canal, as haul them to the Watch's headquarters. The city thus closes up tightly and would-be merry-makers go out in large groups and armed.
Ilthmar is a inward-looking city. Much of its life goes on behind closed doors and although it is a bustling hub of commerce, it is not regarded as especially welcoming to visitors. They are tolerated for trade and valued for their novelty value - little else. It is a city of secrets...
There is a more detailed map of Kalamar island here, with the sites of the monster's killings from the adventure No Night So Dark indicated.
Map of the Danluccë citadel, the home of the watchwarden.