diff --git a/docs/make.jl b/docs/make.jl
index 87c5298..ef625f8 100644
--- a/docs/make.jl
+++ b/docs/make.jl
@@ -5,4 +5,9 @@ Pkg.activate("../")
 using LatticeGPU
 
 makedocs(sitename="LatticeGPU", modules=[LatticeGPU], doctest=true,
+         pages = [
+             "LatticeGPU.jl" => "index.md", 
+             "Space-time" => "space.md",
+             "Groups and algebras" => "groups.md"
+             ], 
          repo = "https://igit.ific.uv.es/alramos/latticegpu.jl")
diff --git a/docs/src/blocks.png b/docs/src/blocks.png
new file mode 100644
index 0000000..91ffd3b
Binary files /dev/null and b/docs/src/blocks.png differ
diff --git a/docs/src/space.md b/docs/src/space.md
new file mode 100644
index 0000000..a32b600
--- /dev/null
+++ b/docs/src/space.md
@@ -0,0 +1,28 @@
+
+# Lattice structure
+
+D-dimensional lattice points are labeled by two ordered integer
+numbers: the point-in-block index ($$b$$ in the figure below) and the
+block index ($$r$$ in the fire below). the routines [`up`](@ref) and
+[`dw`](@ref) allow you to displace to the neighboring points of the
+lattice. 
+![blocks](blocks.png "D dimensional lattice points are labeled by its
+index (a `Tuple` of integers). Given a point (by its index), there are
+routines to jump to neighboring points.")
+
+Directions are numbered fro 1 to D, and then Euclidean time is always
+assumed to be the last coordinate. Planes are also numbered from 1 to
+$$N(N-1)/2$$. The structure [`SpaceParm`](@ref)
+contains the information of the 
+lattice structure and has to be passed as argument to most routines. 
+
+```@docs
+SpaceParm
+up
+dw
+updw
+point_coord
+point_time
+point_index
+point_color
+```
diff --git a/src/LatticeGPU.jl b/src/LatticeGPU.jl
index de9b226..99306dd 100644
--- a/src/LatticeGPU.jl
+++ b/src/LatticeGPU.jl
@@ -23,7 +23,7 @@ include("Space/Space.jl")
 
 using .Space
 export SpaceParm
-export up, dw, updw, point_coord, point_index, point_time
+export up, dw, updw, point_coord, point_index, point_time, point_color
 export BC_PERIODIC, BC_OPEN, BC_SF_AFWB, BC_SF_ORBI
 
 include("Fields/Fields.jl")
diff --git a/src/Space/Space.jl b/src/Space/Space.jl
index f0df405..5726454 100644
--- a/src/Space/Space.jl
+++ b/src/Space/Space.jl
@@ -19,6 +19,27 @@ const BC_SF_ORBI  = 1
 const BC_SF_AFWB  = 2
 const BC_OPEN     = 3
 
+"""
+    struct SpaceParm{N,M,B,D}
+
+This structure contains information about the lattice being simulated. The parameters that define the structure are
+- `N`: The number of dimensions
+- `M`: The number of planes (i.e. \`\` N(N-1)/2 \`\`)
+- `B`: The boundary conditions in Euclidean time. Acceptable values are
+    - `BC_PERIODIC`: Periodic boundary conditions
+    - `BC_SF_AFWB`: Schrödinger Funtional Aoki-Frezzoptti-Weisz Choice B.
+    - `BC_SF_ORBI`: Schrödinger Funtional orbifold constructions.
+    - `BC_OPEN`: Open boundary conditions.
+
+The structure conatins the following components:
+- `iL`: Tuple containing the lattice length in each dimension.
+- `plidx`: The directions of each plane
+- `blk`: The block size in each each dimension
+- `rbk`: The number of blocks in each dimension
+- `bsz`: The number of points in each block
+- `rsz`: The number of blocks in the lattice
+- `ntw`: The twist tensor in each plane
+"""
 struct SpaceParm{N,M,B,D}
     ndim::Int64
     iL::NTuple{N,Int64}
@@ -148,7 +169,7 @@ function Base.show(io::IO, lp::SpaceParm{N,M,B,D}) where {N,M,B,D}
 end
     
 """
-    function up(p::NTuple{2,Int64}, id::Int64, lp::SpaceParm)
+    up(p::NTuple{2,Int64}, id::Int64, lp::SpaceParm)
 
 Given a point `x` with index `p`, this routine returns the index of the point
 `x + a id`. 
@@ -175,7 +196,7 @@ Given a point `x` with index `p`, this routine returns the index of the point
 end
 
 """
-    function dw(p::NTuple{2,Int64}, id::Int64, lp::SpaceParm)
+    dw(p::NTuple{2,Int64}, id::Int64, lp::SpaceParm)
 
 Given a point `x` with index `p`, this routine returns the index of the point
 `x - a id`. 
@@ -201,7 +222,7 @@ Given a point `x` with index `p`, this routine returns the index of the point
 end
 
 """
-    function updw(p::NTuple{2,Int64}, id::Int64, lp::SpaceParm)
+    updw(p::NTuple{2,Int64}, id::Int64, lp::SpaceParm)
 
 Given a point `x` with index `p`, this routine returns the index of the points
 `x + a id` and `x - a id`. 
@@ -246,6 +267,11 @@ end
 @inline cntr(nr, id::Int64, lp::SpaceParm) = mod(div(nr-1,lp.rbkS[id]),lp.rbk[id])
 @inline cnt(nb, nr, id::Int64, lp::SpaceParm)  = 1 + cntb(nb,id,lp) + cntr(nr,id,lp)*lp.blk[id]
 
+"""
+    point_coord(p::NTuple{2,Int64}, lp::SpaceParm{N,M,B,D}) where {N,M,B,D}
+
+Returns the cartesian coordinates of point index `p`
+"""
 @inline function point_coord(p::NTuple{2,Int64}, lp::SpaceParm{2,M,D}) where {M,D}
 
     i1 = cnt(p[1], p[2], 1, lp)
@@ -301,11 +327,20 @@ end
     return CartesianIndex{6}(i1,i2,i3,i4,i5,i6)
 end
 
+"""
+    point_time(p::NTuple{2,Int64}, lp::SpaceParm{N,M,B,D}) where {N,M,B,D}
+
+Returns the Euclidean time coordinate of point index `p`
+"""
 @inline function point_time(p::NTuple{2,Int64}, lp::SpaceParm{N,M,B,D}) where {N,M,B,D}
     return cnt(p[1], p[2], N, lp)
 end
 
+"""
+    point_index(pt::CartesianIndex, lp::SpaceParm)
 
+Given the cartesian coordinates of a point, returns the point index
+"""
 @inline function point_index(pt::CartesianIndex, lp::SpaceParm)
 
     b = 1
@@ -319,7 +354,7 @@ end
 end
 
 """
-    function point_color(p::NTuple{2,Int64}, lp::SpaceParm)
+    point_color(p::NTuple{2,Int64}, lp::SpaceParm)
 
 Returns the sum of the cartesian coordinates of the point p=(b,r).
 """
@@ -334,7 +369,7 @@ Returns the sum of the cartesian coordinates of the point p=(b,r).
 end
 
 
-export up, dw, updw, point_index, point_coord, point_time
+export SpaceParm, up, dw, updw, point_index, point_coord, point_time, point_color
 export BC_PERIODIC, BC_OPEN, BC_SF_AFWB, BC_SF_ORBI
 
 end