Compiled: 2026-08-21 · Replaces the research report of Nov. 2024 · Status: draft
About this document. This is the source dossier behind the texts and the narration for this site. It was compiled in August 2026 with AI assistance under named editorial responsibility (see About Heritage Navigator), and it replaces an earlier, AI-generated research report from November 2024 that mixed sourced facts with unsourced and invented material. The dossier was written in Danish as the working document and translated into English for this page; Portuguese place names, quotations and source titles are kept in the original.
Every factual statement carries a source number [n], referring to the source list in section 6, and a confidence grade:
Legends and traditions are kept in their own section, with a source for the fact that the story is told, not for its truth. Claims that could not be verified, or that were rejected, are listed separately so that the reader can see what was left out and why. Quotations are reproduced only where the wording was seen in the source. Dead links are recorded as dead, with the date, rather than omitted; where a page exists only in the Internet Archive, the archive URL is given. Section 5 lists what would take an archive, the municipality, the museum or a historian to settle.
Ruined bastioned coastal fort in the Sapal do Rato, c. 2 km south-east of Tavira at the mouth of the Gilão, among salt pans and today inside the Parque Natural da Ria Formosa [1][2]. Begun in the 1570s under D. Sebastião on the then Ilha das Lebres to cover the bar and the harbour; the bar migrated eastwards while building was under way, work came to a halt in the early 17th century, and the two landward bastions were demolished [1]. Resumed in 1654 under D. João IV and renamed Forte de Santo António, but after the Forte de São João da Barra (1656-72) further east it had only a secondary role [1][2][9]. From 1792 solely a powder magazine, abandoned around 1830 (SIPA) or 1840 (DGPC); listed IIP by Decreto n.º 8/83 [1][2]. Consolidated in 1981, on the Revive list since 2016, still "procedimento em preparação" [1][3].
| Claim | Source | Grade |
|---|---|---|
| Names: Forte do Rato; Fortaleza/Forte de Santo António; Forte da Ilha das Lebres (SIPA IPA.00002823; DGPC "Forte do Rato") | [1][2] | A |
| Isolated in the Sapal do Rato, c. 2 km SE of the town at the mouth of the Gilão; originally on the Ilha das Lebres, now joined to the mainland by silting; salt pans nearby; WGS84 37.12146 / -7.62144 | [1][2] | A |
| In the Parque Natural da Ria Formosa; access by road from the roundabout at the end of Rua Almirante Cândido dos Reis, then a dirt track | [1] | A |
| Listed IIP: Decreto n.º 8/83, DR 1.ª série n.º 19, 24-1-1983 | [1][2][5] | A |
| 1530: Tavira asks D. João III for four caravels against Algerian pirates; refused 30 April | [1] | A |
| 1562, 12 Dec.: the Cortes decide that "no Algarve se façam fortalezas onde pareçam necessárias" | [1] | A |
| Begun in the 1570s under D. Sebastião (governor D. Diogo de Sousa) on an island opposite the new bar, to cover the harbour entrance and the town | [1][2][4] | A |
| 1573: during the king's visit João Gascão writes that "o senhor D. Duarte foi pelo rio abaixo num batel ver o sítio da fortaleza, que ora fez, e viu outra que está feita de torreões" (Torreão do Lastro) | [1] | A |
| 1577: a note places the natural bar off the "Fortaleza de Santo António" | [5] | B |
| The coastline and the bar changed during construction; the bar migrated eastwards and took away the fort's defensive value | [1][2][4][5] | A |
| The original design is unknown; it is attributed to the Italian engineer "João Maria Benette" (SIPA) / "João Maria Beneditte" (Massai 1621 via Guedes 1988) — Postal/NatGeo write "Giovanni Maria Benedetti" | [1][7] | A/C |
| 1617: Alexandre Massai's report: "está principiado um forte de cinco baluartes", three towards the sea five palmos above the cordon, two towards the land 15 palmos high; well; cost over 30,000 cruzados, 20,000 more to complete; "Dizem que começou em tempo de El-Rei Dom Sebastião", abandoned "por se mudar a barra para levante" or because of the cost | [1] | A |
| Massai's drawing shows five bastions (three towards the bar, two towards the land), a stone-paved moat ("lajeado") apparently meant to be filled with water, and a covered way in tenaille form | [1][7] | A |
| 1621: Massai proposes demolition and reuse of the stone in the Torreão do Lastro or North Africa; the fort continues, but the two landward bastions are demolished without trace | [1] | A |
| 1654: D. João IV orders work resumed (governor conde de Reis); the fort is renamed Forte de Santo António de Tavira | [1][7][6] | A |
| DGPC's record claims, by contrast, that "Fortaleza de Santo António" was the name "à época da sua fundação" | [2] | A (contradicts [1]) |
| 1656-1670/72: Forte da Conceição / São João da Barra is built at Gomeira; Forte do Rato gets "exclusivamente as funções de registo" (SIPA); DGPC: secondary role, but renewed to "reforçar a linha de fogo do novo baluarte" | [1][2][9] | A |
| Forte de São João da Barra: ordered 1656 by Nuno de Mendonça, 2.º conde de Vale de Reis, completed 1672, four bastions, IIP, sold to private owners 1905, today a tourism business | [9] | B |
| 1717: a note confirms that the bar now lay off Gomeira | [5] | B |
| 1753, 14 April: engineer Pedro de Santa Colomba: a "Fortim o qual não é defensa nenhuma"; the bastions reach only 15 palmos and cannot bear artillery; the governor builds a bridge at his own expense so that the fort can be reached on foot at low tide | [1] | A |
| 1788: José de Sande Vasconcelos draws a plan with a drawbridge over a water channel in front of the gate | [1] | A |
| 1788/1792: nine men and two cannon, one of them without equipment; functions solely as a powder depot | [1][7][5] | A |
| 1821: no artillery, the gate half destroyed, the powder in a roofless magazine; Wikipedia: only three men | [1][5] | A/B |
| Abandonment: SIPA — 1830 on the orders of brigadier visconde de Molelos (governador de Armas do Algarve), too costly to maintain and to reach overland; DGPC/Revive/visitartavira/pt.wiki — garrison withdrawn 1840; report 20-11-1875 — "abandonado desde 1825 ou 1826" | [1][2][3][4][5] | A |
| 1863: "um reduto quadrado, abandonado há muitos anos"; the land around had been cultivated "e deu bom centeio"; the high part of the marsh is not reached by the tide | [1] | A |
| 1875: "em completa ruína e abandono, tendo sido roubados quase todos os materiais mais importantes, como cantaria, lagedo, tijolo e telha"; the roots of the fig trees "terrível inimiga das construções" | [1] | A |
| 1882-1938: the land and the fort are leased for grazing, including to the municipality 1888-92 for "gado dos lamares pobres do concelho" | [1] | A |
| 1939: the Ministério da Guerra transfers the "fortaleza em completa ruína" (plot 75,064 m²) to the Ministério das Finanças | [1] | A |
| 1979: the municipality warns that the fort is in danger of collapse; 1981: DGEMN consolidates sections of wall, excavates at the gate for the stones of the gate arch and removes fig trees | [1] | A |
| 1998: protocol DGEMN–Câmara de Tavira on restoration and a "núcleo museológico Museu do Mar"; 1999-2000: the municipality clears, excavates superficially and puts up signs; PROALGARVE application 2000 | [1][2] | A |
| 2016, 27 Dec.: on the list of c. 30 state properties for Revive; the Revive page (2026-08-21): "Procedimentos em preparação", gross floor area 180.44 m² | [1][3] | A |
| Present plan: straight land front facing NW with portal in rusticated ashlar and masonry bridge over a partly filled-in moat; three bastions towards the SE/the bar, the middle one largest with a raised battery; remains of powder magazine, guardhouse, barracks, governor's house; well (mentioned 1617); later guarita | [1][2][4] | A |
| Frei João de São José (1577) on the Algarve coast: "muro e fortaleza a cuja sombra o Reino se tem por seguro" (via Moreira 1986 in the DGPC record) | [2] | A |
| Ownership: public, state; "devoluto" | [1] | A |
| The municipality's list of places calls the adjacent salt pans "Salinas perto do Forte do Rato" | [11] | A |