Lesson Plan

Coquina: The Mighty Tiny Shell

Aerial view of the Castillo de San Marcos
Arial View of the Castillo de San Marcos

NPS Photo/VIP Cipriani

Grade Level:
Fourth Grade
American Indian History and Culture, Colonial History, Hispanic or Latino American History and Culture, History, Mathematics, Social Studies
Lesson 1 hr 15 minutes or each activity can be done separately.
Group Size:
Up to 24


In this lesson, students will learn about coquina and why the material was chosen to construct the fort.


The students will understand the importance of historical documents, how they are used to decipher history. Students will practice using historical documents, summarizing and synthesing information. Students will also practice unit conversions and solving real world problems using volume and area formulas.


Florida's position on the life line connecting Spain with her colonies gave this sandy peninsula certain strategic importance. Spain knew
that Florida must be defended to prevent enemies from using the harbors as havens from which they could spread their sails against Spanish commerce.
Besides, Florida's lee shores and deadly reefs combined with hurricanes in the narrow Bahama Channel to wreck many a good ship. Scores of mariners were cast ashore on the inhospitable coast. Florida had to be made safe for them, as well
as unsafe for enemies.

It was a sizable defense problem. The French triggered the solution in 1564 with Fort Caroline, a colony named for their teenage King
Charles, near the mouth of Florida's St. Johns River. The French settlement drew Spanish Admiral Pedro Menéndez de Aviles to Florida in 1565. He
established the St. Augustine colony and forthwith removed the Frenchmen, some of whom had already begun piratical careers. Now, with this small fortified settlement on one side of the Bahama Channel and growing Habana on the other, Spanish ships could normally pass safely from the ports of Nueva España to those of the Old Country.

Although the real construction was not even started, great obstacles had already been overcome. Very little masonry had ever been done in the presidio and, with the exception of the imported artisans, the workmen had to be trained. Even the imported ones had much to learn about coquina, the natural shellstone peculiar to this part of Florida. Coquina consists of broken sea shells cemented together by their own lime. Where a shelly stratum was under great geological pressure, the stone is solid and relatively hard;where conditions were less favorable, it is
coarse and easily crumbled. The men had to become expert in grading the stone, for only the best of it could go into the walls.

There was also a shortage of common labor. When there should have been 150 men to keep the 15 artisans
working at top speed-50 in the quarries and hauling stone, 50 for gathering oyster shells and helping at the kilns, and another 50 for digging the
foundation trenches, toting the excavation baskets, and mixing mortar-it was hard to get as many as 100 laborers on the job.

Indians from three nations, the Guale (coastal Georgia), Timucua (Florida east of the Aucilla River) and
Apalache (between the Aucilla and the Apalachicola), were tapped for manpower. True, they were paid labor, but some had to travel 80 leagues to reach the presidio, and many served unwillingly. The Spanish levies for labor caused serious domestic problems, for the draftees had either to bring their families
along or else leave them in the home villages to eke out their own living. In theory each complement of Indian labor served only a certain length of time;in
practice it was not uncommon for the men to be held long past their assigned time, either through necessity or carelessness. In some cases, not even the chiefs were exempt from the draft.



The summary students construct after reading What is Coquina will allow the teacher to know if the student can summarize and sequence correctly. The students' journal response for the Castle has Begun may be used to informally assess the students' understanding of how life was like in St. Augustine at the time of the construction of the fort, 1672. Teachers may use the math problem solving with area and volume worksheet as an assessment.

Park Connections

To teach students about the importance of historical documents, understanding primary sources and the construction of the Castillo de San Marcos. This lesson uses primary sources such as the Affidavit Recording the Groundbreaking Ceremony for Castillode San Marcos,October 2, 1672 by JN MORENO Y SEGOVIA. By analyzing this account, students will better understand need to build the Castillo de San Marcos and the overall tone of the event. Also, students will understand the rare and expensive nature of coquina and the process in which it forms.


From Readings:  Coquina, acidic, calcium carbonate, mortar
Important People:  Sir Frances Drake, Robert Searles, Pedro Menendez

Last updated: April 14, 2015