diff --git a/src/bitboard.rs b/src/bitboard.rs
index b4c18d3..3c920ca 100644
--- a/src/bitboard.rs
+++ b/src/bitboard.rs
@@ -1,22 +1,28 @@
+//! Sets of squares.
+
 use crate::board::*;
 
 use std::iter::ExactSizeIterator;
 use std::iter::FusedIterator;
 
+/// A set of squares.
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct Bitboard(pub(crate) u64);
+pub struct Bitboard(pub u64);
 
 impl Bitboard {
+    /// Returns an empty bitboard.
     #[inline]
     pub fn new() -> Self {
         Self(0)
     }
 
+    /// Returns `true` if the bitboard is empty.
     #[inline]
     pub fn is_empty(&self) -> bool {
         self.0 == 0
     }
 
+    /// Returns the square with the smallest index that is present in the bitboard.
     #[inline]
     pub const fn first(&self) -> Option<Square> {
         let mask = self.0;
@@ -27,7 +33,7 @@ impl Bitboard {
     }
 
     #[inline]
-    pub const fn last(&self) -> Option<Square> {
+    pub(crate) const fn last(&self) -> Option<Square> {
         let mask = self.0;
         match mask {
             0 => None,
@@ -37,6 +43,7 @@ impl Bitboard {
         }
     }
 
+    /// Removes the square with the smallest index and returns it, or `None` if the bitboard is empty.
     #[inline]
     pub fn pop(&mut self) -> Option<Square> {
         let Self(ref mut mask) = self;
@@ -48,13 +55,33 @@ impl Bitboard {
         square
     }
 
+    /// Inserts a square in the bitboard.
     #[inline]
     pub const fn insert(&mut self, square: Square) {
         self.0 |= 1 << square as u8;
     }
 
+    /// Removes a square from the bitboard.
     #[inline]
-    pub fn trans(&self, direction: Direction) -> Self {
+    pub const fn remove(&mut self, square: Square) {
+        self.0 &= !(1 << square as u8);
+    }
+
+    /// Returns `true` if the bitboard contains the given square.
+    #[inline]
+    pub const fn contains(&self, square: Square) -> bool {
+        self.0 & (1 << square as u8) != 0
+    }
+
+    /// Returns the vertical symmetry of the bitboard.
+    #[inline]
+    pub fn mirror(self) -> Self {
+        let [a, b, c, d, e, f, g, h] = self.0.to_le_bytes();
+        Self(u64::from_le_bytes([h, g, f, e, d, c, b, a]))
+    }
+
+    #[inline]
+    pub(crate) fn trans(&self, direction: Direction) -> Self {
         match direction {
             Direction::North => Self(self.0 << 8),
             Direction::NorthEast => Self(self.0 << 9) & !File::A.bitboard(),
@@ -66,16 +93,39 @@ impl Bitboard {
             Direction::NorthWest => Self(self.0 << 7) & !File::H.bitboard(),
         }
     }
+}
 
-    #[inline]
-    pub const fn contains(&self, square: Square) -> bool {
-        self.0 & (1 << square as u8) != 0
-    }
-
-    #[inline]
-    pub fn mirror(self) -> Bitboard {
-        let [a, b, c, d, e, f, g, h] = self.0.to_le_bytes();
-        Self(u64::from_le_bytes([h, g, f, e, d, c, b, a]))
+impl std::fmt::Debug for Bitboard {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+        f.write_str("Bitboard(")?;
+        if f.alternate() {
+            for rank in Rank::all().into_iter().rev() {
+                f.write_str("\n   ")?;
+                for file in File::all() {
+                    f.write_str(if self.contains(Square::new(file, rank)) {
+                        " 1"
+                    } else {
+                        " ."
+                    })?;
+                }
+            }
+            f.write_str("\n)")?;
+        } else {
+            for rank in Rank::all().into_iter().rev() {
+                if rank != Rank::Eighth {
+                    f.write_str("/")?;
+                }
+                for file in File::all() {
+                    f.write_str(if self.contains(Square::new(file, rank)) {
+                        "1"
+                    } else {
+                        "."
+                    })?;
+                }
+            }
+            f.write_str(")")?;
+        }
+        Ok(())
     }
 }
 
diff --git a/src/board.rs b/src/board.rs
index 9833d61..7f41659 100644
--- a/src/board.rs
+++ b/src/board.rs
@@ -136,7 +136,7 @@ impl File {
     }
 
     #[inline]
-    pub(crate) const fn bitboard(self) -> Bitboard {
+    pub const fn bitboard(self) -> Bitboard {
         Bitboard(0x0101010101010101 << (self as u8))
     }
 
@@ -213,7 +213,7 @@ impl Rank {
     }
 
     #[inline]
-    pub(crate) const fn bitboard(self) -> Bitboard {
+    pub const fn bitboard(self) -> Bitboard {
         Bitboard(0xFF << ((self as u64) << 3))
     }
 
@@ -294,7 +294,7 @@ impl Square {
     }
 
     #[inline]
-    pub(crate) const fn bitboard(self) -> Bitboard {
+    pub const fn bitboard(self) -> Bitboard {
         Bitboard(1 << self as u8)
     }
 
diff --git a/src/lib.rs b/src/lib.rs
index 6b5e3c5..7df0d27 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -73,10 +73,10 @@
 //! - etc.
 
 pub(crate) mod array_vec;
-pub(crate) mod bitboard;
 pub(crate) mod lookup;
 pub(crate) mod magics;
 
+pub mod bitboard;
 pub mod board;
 pub mod position;
 pub mod san;