Gruta do Lago Azul
The entrance to Bonito's best-known show cave, a protected Natural Monument with a blue underground lake where divers found Ice Age mammal bones in 1992. Visits are guided walks; no public diving offer was found.
Visitors enter through a circular opening about 40 m across and walk down a steep chamber towards the lake on guided tours. The lake itself is not open to visitors in any source reviewed: the 2012 state order covered contemplative visits only.
The site matters to cave diving for what divers found there. In 1992 Brazilian and French divers recorded bones of extinct Pleistocene mammals on the lake floor, and the lake hosts cave-adapted aquatic life, including the blind crustacean Potiicoara brasiliensis.
环境
A large, steeply sloping dry chamber ending in a still, clear underground lake. A 2002 report gave the lake as 90 m deep. Sunlight strikes the water in part of the year, turning it an intense blue.
环境条件
Light effect on the lake is strongest from about September to February according to a 2021 report; other sources give different months and morning hours.
典型范围来自已发表资料，不代表当前实际状况。
设施
Guided walking route into the cave. Showcaves.com lists tours of about 90 minutes and no entry for children aged 0 to 4 (data from 2000 to 2020).
本页所有信息及其来源 (9)
| 信息条目 | 状态 | 来源 |
|---|---|---|
| The entrance is circular and about 40 m across. | 已报告 | [3] |
| The underground lake is 90 m deep.Single 2002 figure; no survey found. | 信息可能已过时 | [4] |
| In 1992 Brazilian and French divers found Pleistocene mammal bones on the lake floor. | 已报告 | [4] [5] |
| The 2012 IMASUL order authorised contemplative visits only, capped at 305 visitors a day in groups of up to 15 with a guide, and does not mention diving.Authorisation ran to 2013-12-31; later visitor rules are in the 2022 management plan, which could not be read for this record. | 信息可能已过时 | [1] |
| IMASUL approved the monument's management plan on 12 July 2022. | 已核实 | [2] |
| The federal government authorised ceding the cave to Bonito municipality for 20 years in January 2021, with the municipality managing visits. | 已报告 | [3] |
| Visits required a registered local guide, a voucher único, a helmet and closed rubber-soled shoes under the 2012 order.2012 rules. | 信息可能已过时 | [1] |
| From September to February sunlight on the lake turns the water an intense blue.Showcaves gives about 07:30-09:30 each morning; FAPESP (2002) gives December and January. | 已报告 | [3] |
| Showcaves lists guided tours of about 90 minutes and no entry for children aged 0 to 4.Reference data dated 2000-2020. | 信息可能已过时 | [5] |
已核实：来自我们直接查阅的官方或主要来源。已报告：仅来自二手来源。来源存在冲突：注释中列出两种版本。可能已过时：我们找到的最新来源已有一定年代。
由我们根据上述来源以自己的文字整理撰写。 提交更正