Gwaith-i-erain?

[Bloodly]

This building is buildable by the Silvan Elves. It does nothing. In the files, it's called 'greek_flora'. Its entry is as follows:

greek_flora city requires factions { mongols, }
{
capability
{
population_growth_bonus bonus 1 requires factions { mongols, } and event_counter is_the_ai 1
}
material wooden
construction 4
cost 7500
settlement_min town
upgrades
{
m_greek_flora
}
}
m_greek_flora city requires factions { mongols, }
{
capability
{
population_growth_bonus bonus 2 requires factions { mongols, } and event_counter is_the_ai 1
}
material wooden
construction 5
cost 10000
settlement_min large_town
upgrades
{
}

What precisely is it meant to be doing for the player? I'm presuming the entries for what it's meant to do for the player as opposed to the AI were missed somewhere along the line.

[UniformKilo96]

It looks like it doesn't do anything. Only the AI get population growth bonus.

[Ngugi]

So it is, that building has no direct bonus for the player.
It might been of use for guilds in older versions but not in 3.2

You can change this to apply for the player too by deleting this part:

population_growth_bonus bonus 2 requires factions { mongols, } and event_counter is_the_ai 1