Ancients is the third release from Black Lung. I can honestly say I've never heard the first two, but the trio made a real impression on me here and I am sure I'll seek out the rest of their catalog at some point as a result.
This genre is based off of killer guitar lines played at half-speed, surrounded by serviceable accompaniment. There are dozens of groups inspired by Master of Reality and Sleep's Dopesmoker, but it takes real skill to break off from the rest and standout. Black Lung gave enough on Ancients to do just that behind a fantastic vocal performance, solid guitar work, inspired drum work, and good production quality. If this had been released a few decades ago, Black Lung would have been stars.
Ancients is a basically a love story to the genre, and I suggest all fans of stoner rock to seek this great album out.