Set pieces, such as the hub of my new campaign, are really just more complicated groupings of problems, threats, resources, and rewards.
Water Street
Problem
Located not far from the bustle of the Guildsmen district, Water Street was once home to merchants, bankers, and city officials, but is now in decline as those families move to Oldtown or Rivergate. With the closing of the street's pub, Water Street faces a real danger of becoming a slum. The families and small shops remaining on Lantern Street are increasingly threatened by gangs - whose younger members are often recruited from the Water Street orphanage. The community also lacks leadership, with the closest thing being a foolish grocer who deliberately antagonizes the gangs.
Resource
At the end of Water street lies the Lantern, a small lighthouse that lights the way to a small set of docks there. Unbeknownst to the residents, one large lantern inside of the lighthouse is home to a Lantern Archon. This archon is rarely active, spending most days contemplating the connection between physical light and spiritual goodness, but with the current danger to the area he may become more active, speaking to the occasional adventurer or even animating the lantern in which he dwells.
Resource with hook to Threats
Those who have lived there know about the connected cellars beneath many of the houses on Water Street, even running across the road (these date from an earlier period of the city and luckily do not experience seepage from the sewers). A few loose stones in the cellars hide a tunnel to ruins from even earlier incarnations of the city - if it is not discovered soon by a PC, it may become an entry point for monsters that dwell beneath the city.
Reward
At the very end of the street is a hub of a few roads, where they meet at the circular Wyrrith Park. Wyrrith Park is known for the Wyrring Tree, a large oak watched over by a dryad who, though seldom seen, is subject of many local folk tales. The Wyrrith Park is the main location for the holidays celebrated by the people of Lantern Street and is large enough to host a small fair (although this is definitely a local park - the rest of the city celebrates holidays elsewhere, especially in the market district). Both the dryad and Wyrrith park can be portrayed as rewards for nature-loving PCs, especially after any threat to the area. If that portrayal does not work for your campaign, the dryad of the Wyrring tree is also an adept healer. If Gnolls have a chance to raid the area, this could also be a springboard for
The Missing Dryad
Resource with possible Problem
Water street is also home to a talented but not very respected alchemist, who operates a lab in the basement against municipal bylaws.