Here is a
nice index of 4E adventures. I don't know which are good, though.
They don't list any adventures for 16th level, per se. So I've copied 13th - 15th level adventures below:
13th Level
Brink of Madness (Dungeon 163 - Madness Trilogy) - By Robert J. Schwalb
The Madness trilogy concludes with "Brink of Madness." The heroes must set off to stop an insane cultist from tearing open a hole in reality to a world of unimaginable horror. Failure means that the entire region becomes saturated with mutating energy and creatures capable of shattering the strongest minds. Only the heroes of Wellspring can put a stop to the tortured and twisted Malachi. An adventure for 13th-level PCs.
Clash of Steel (Dungeon 172) - By Jennifer Clarke Wilkes
Barrinsgate was founded by bandit leaders who found common cause, some years ago, and discovered that lawful commerce was a more lucrative pursuit. But the remains of their gangs are still around, and now the largest has begun inexplicably disturbing the fragile peace in town. The heroes must discover who has stirred up the gangs of Barrinsgate before the city falls into chaos. This adventure features material from Draconomicon: Metallic Dragons. An adventure for 13th-level PCs.
In the Depths of Avarice (Dungeon 157) - By Tim Hitchcock
The mine has been known as Tessount’s Folly for years, due to it producing nothing of value. Now Valmour, the youngest son of the mine’s late owner, has inherited the mine . . . and found something he should have left buried.
Monument of the Ancients (Dungeon 170) - By Brian R. James and Matt James
Barbarian attacks in the Moonsea North send panicked refugees pouring into the port city of Phlan. Something ominous and ancient drives the horse nomads to attack their neighbors. Poised to shatter the ancient monument keeping him from Faerûn, a "lost god" from Toril's past sends an agent from the Elemental Chaos to herald his long prophesized return. An adventure for 13th-level PCs.
Web of Chains (Dungeon 168) - By Owen K.C. Stephens
Slavers have come to the Kragholm region, and the former-slaveholder citizens of settlements such as Elmhollow have come to appreciate the yolk of servitude in an all-too uncomfortable manner. But the group of Underdark slave traders have larger plans in mind, and the PCs must act to stop a slave empire from rebuilding. An adventure for 13th-level PCs.
14th Level
Alliance at Nefelus (Dungeon 165 - Scales of War AP) - by Chris Tulach
The Scales of War Adventure Path continues. The characters are dispatched with their deva ally Amyria to the island nation of Nefelus, home of sages and masters of the arcane. The nation is a vital potential ally in the war against the githyanki, but none of the emissaries from the defending nations have returned. As the PCs soon discover, a new enemy has blockaded the nation, and the heroes must end the blockade and help persuade Nefelus to join their cause. An adventure for 14th-level PCs.
15th Level
Garaitha's Anvil (Dungeon 167 - Scales of War AP) - By Scott Fitzgerald Gray
The Scales of War Adventure Path continues. The githyanki are on their heels after suffering losses on the mortal world and in the Feywild. The PCs have the opportunity to strike a telling blow for their world as they undertake a mission of certain death at a githyanki stronghold and planar nexus. But how can a small group of adventurers possibly hope to defeat a fortress filled to the brim with angry, fighting githyanki? An adventure for 17th-level PCs.
Sea Reavers of the Shrouded Crags (Dungeon 158) - By Logan Bonner
A group of mysterious sea raiders—capable of appearing out of nowhere, striking, and disappearing—has terrorized a group of coastal states for some time. Now the leader of the states has asked the characters to infiltrate the raiders, find out how they operate, and put a stop to their activities. But once the heroes join the raiders, things aren't as clear as they seemed at the start. Will they succeed at their mission? Or join the raiders themselves? An adventure for 15th-level PCs.
Throne of the Stone-Skinned King (Dungeon 166 - Scales of War AP) - By Logan Bonner
The Scales of War Adventure Path continues. The characters travel to the Feywild with the Seed of Winter, an artifact recovered from a powerful foe. There, they discover a plot among the retinue of a mad fomorian king, as more alliances to the githyanki invaders reveal themselves. An adventure for 15th-level PCs.
