diff --git a/croaring/src/lib.rs b/croaring/src/lib.rs
index 6d17ccc..680262d 100644
--- a/croaring/src/lib.rs
+++ b/croaring/src/lib.rs
@@ -1,3 +1,8 @@
+#![deny(missing_docs)]
+//! Rust wrapper for `CRoaring` (a C/C++ implementation at <https://github.com/RoaringBitmap/CRoaring>)
+//!
+//! Provides Compressed Bitmaps, which act like a set of integers in an efficient way.
+
 pub mod bitmap;
 pub mod bitset;
 pub mod treemap;
diff --git a/croaring/src/treemap/iter.rs b/croaring/src/treemap/iter.rs
index 7c587f0..d25504a 100644
--- a/croaring/src/treemap/iter.rs
+++ b/croaring/src/treemap/iter.rs
@@ -30,6 +30,9 @@ type InnerIter<'a> = iter::FlatMap<
     fn((&'a u32, &'a Bitmap)) -> To64Iter<'a>,
 >;
 
+/// Iterator over values stored in the treemap
+///
+/// Values are ordered in ascending order
 pub struct TreemapIterator<'a> {
     iter: InnerIter<'a>,
 }
diff --git a/croaring/src/treemap/mod.rs b/croaring/src/treemap/mod.rs
index 57eeca8..ca2aa53 100644
--- a/croaring/src/treemap/mod.rs
+++ b/croaring/src/treemap/mod.rs
@@ -31,7 +31,11 @@ mod util;
 pub use iter::TreemapIterator;
 pub use serialization::{Deserializer, Serializer};
 
+/// A RoaringBitmap-based structure that supports 64bit unsigned integer values
+///
+/// Implemented as a [`BTreeMap`] of [`Bitmap`]s.
 #[derive(Clone, PartialEq, Eq)]
 pub struct Treemap {
+    /// The underlying map of bitmaps
     pub map: BTreeMap<u32, Bitmap>,
 }