Architecturally thus far the Mask Temple at Lamanai has had more major phases of construction identified (5) then any other structure.  These span a time period of over 1,000 years from 100 BC to AD 900.  It is the furthest north structure on the main site tour and was constructed on a large platform that holds 4 other smaller temples.

Very little of this phase is visible today - see the location of this structure in the map above - the detailed stucco façade that ornamentally decorates this early structure resembles masks located at the ancient Maya site of Cerros – this site is located approximately 90 river miles north of Lamanai  

Early Classic Phase, Mask Temple –
AD 450 - 500

During this phase, as with all the others, major modifications to this building are done only to the front, the sides and back are simply maintained.  It is during this phase for the first time we see the façade sculptures that represent a human face and flank the center stair.  

Middle Classic Phase, Mask Temple –
AD 500 – 550

Again a frontal modification only, a small front platform is added and the upper masks are partially destroyed by the Maya when they decided to cover them up.

Late Classic Phase, Mask Temple – 
AD 550 - 625

Major frontal modifications, all façade mask sculptures covered up, a Lamanai Building Type (LBT) and lower side stairs are added.  Characteristics of the LBT is that they are set lower on the structure (instead of the top) and set across the main central stair.  

Late Classic Phase, Mask Temple –
AD 625 – 900

Yet again another major frontal modification this time the LBT is placed a bit higher and two outer front terraces are constructed that support the building.

AD 500 – Classic Period façade sculpture on Structure N9-56 (Mask Temple)

During the Classic period there was a rise in kinship and rulership 'worship', less representations of deities and gods (although still present) – during the Early Classic period at Lamanai we see this large façade mask that certainly represents a human figure, whether this is a depiction of one of Lamanai's ruler or an even higher power is uncertain, although one of the only two tombs recovered at Lamanai was recovered within this structure and dates to this time period (see below)

This mask is constructed of individual blocks of limestone from which the relief is sculpted.  This is a different style of construction because traditionally the Maya place a fair amount of plaster over limestone and then carve the relief into that.

Late Classic (AD 500) tomb, Structure N9-56 (Mask Temple)

One of only a few tombs recovered thus far at Lamanai, discovered by trenching the structure along the primary axis – considered a vaulted eccentric elite burial by D. Pendergast – the individual was found to be in a cocoon chamber with a wooden frame plastered with coarse textiles soaked in lime – the human remains had been encased with a red pigment (most likely cinnabar based) and then covered in clay to help slow decomposition – the pelvis of the individual was placed within a large Classic period plate decorated with a hummingbird