Old Fort at San Juan del Sur?

Hello, I’m looking for any kind of information about a fort located in San Juan del Sur, Nicaragua. Supposedly it was built in the 1850′s during the Gold rush and Vanderbilt’s transit route through Nicaragua.

Do you have any records of this fort? Can you point me where to look for this? Here in Nicaragua nobody knows about this fort, it is just there, no history at all!

Thanks for your time,

Editor’s Note: So far the only thing I’ve found is a reference to Castille Viejo and a reference to an old fort without naming that fort. I’ll look when I next go into San Francisco for research.

Daily Alta California, September 18, 1851

“I understand it is the intention of the company to have the steamer in future come down to this rapid (inland on the San Juan River). This rapid is much the largest of the three, but is not, in my opinion, as bad as several on the Chagres river, and we got through it without the least trouble. The second rapid bears the name of Castillo Viejo — old castle — a fort standing on the shore, and the rapid is supposed to have been made by the Spaniards throwing stores and munitions in here at the time of Lord Nelson’s attack upon the country; it is certain he was not able to pass this point.

New York Daily Times, November 3, 1851

. . . Quiet however was soon restored and continued to reign until the arrival at Chagres on the 18th ult., of the Oregon’spassengers. The next day, a native boatman who carried off some passengers to the Cherokee was attached . . . The next morning all was perfectly quiet . . . at about eight o’clock a large number of nataive boats had crossed the river, unsuspicious of any danger, to take off passengers to the steamer . . . a murderous fire was opened upon them, with guns and revolvers, by the American boatmen, assisted by man of the Californians . . . Presently there was a cry of “At castillo” and hundreds of them hurried up the hill to the old fort.

San Juan Del Sur, Sunset, Nicaragua
Jane Sweeney