House entrance in Old Town, Cartagena, Colombia
Walking the streets in the Old Town you could not miss watching the design of the front of most of the houses. Beside colors of the walls, windows, etc it was the entrance itself.
The entrance doors were different. Some had a small dor in the big door. The large door allows for the occasional deliveries while the smaller inset door prevent blasts of hot air from entering as people come and go.
Secondly, these massive doors were one of the easiest ways to protect a home from pirates, privateers, and all the other enemies of the Spanish Crown who prowled the Caribbean and regularly raided Cartagena.
Like the doors themselves, the door knockers held great importance in Colonial Cartagena society.
The overall size of the door knocker denoted the status of the family behind it. Simply put, the bigger the knockers the more important the individual or family. Some of the most elaborate aldabas are made from rarer metals and designed to appear animated when used (a mermaid’s tail flipping back and forth, for instance).
But size wasn’t the only consideration.
As you stroll through the older parts of Cartagena you’ll no doubt notice all sort of figures and symbols (usually animals of some sort). The motif of the door knocker was a quick way to signify the profession of the homeowner. Each design denotes a specific trade, skill, or calling.
For example, marine motifs—turtles, fish, mermaids, and even more fanciful creations—adorned the doors of men who made their living from the sea, such as wealthy merchants and traders. Lions represented teachers, lizards represented royalty, masonic symbols represented builders or engineers, and so on. Think of them as a sort of symbolic sign to let everyone know who lived inside. (Quoted from Cartagena Colombia Rentals)