Dungeon23, Bridge 1.4

Room 1.4: This is a 70 foot long stone bridge connecting the north barbican gatehouse to the Northwest Gate of the Castle. The stone handrail is mostly intact, the surface is heavily scratched and mostly free of moss. 

Two sculptural elements adorn the bridge, one of which is considerably more broken than the handrails. Both stone sculptures appear to be creatures with humanoid torsos and serpentine lower bodies. The more complete of the two is along the railing, it's tail weaving between the railposts, and it reaches towards the castle. The other is inconveniently placed in the middle of the bridge, and its upper half is broken off the snake body, and rests in several pieces. The shattered one is in poor condition generally, but the one weaving through the railing is not only in great shape but also an incredibly detailed carving with lifelike (though inhuman) features and little signs of weathering. 

In reality, these are of course the petrified features of Yuan Ti who died upon the bridge earlier this year. Players will likely grok to this quickly, and the GM should make no effort to conceal it from them if they inquire along those lines. They'll probably draw the wrong conclusion anyway, assuming it to be foreshadowing of a Medusa much later in the module, rather than a basilisk showing up in the next couple of rooms. 

Speaking of which: While most of the time this bridge is empty (other than stone cold snakemen statues), there are two fairly regular exceptions when the creatures from Room 1.XX show up. On cold days, the basilisk comes to sun itself on the bridge for an hour or two in the middle of the day to warm up. At sunset, it's owner takes it out for a 15-minute walk and a frequent snack, often plucking a tasty bat out of the air when the swarms release from 1.1A. At either time, both creatures from 1.XX arrive together.