At the middle of the map, on top of the Island (see right) there are the words "Le Cratère", which is french for "The Crater", there is speculation that this is the name of one of the remaining stations
The crater was caused by the detination of Jughead.
There may not be a hatch there, but rather, it may be the reason the rest of the hatches were built - to study the crater in the center.
The crater is where a certain Falling Star fell to earth.
If Rousseau's map is to be believed the Island is some 240 kilometers (roughly 160 miles) long.
This seems unlikely since many portions of the Island have already been discovered within walking distance. Since Rousseau is French, it is more likely that the map scale was drawn in Kilometers, which would make it roughly 99 miles.
Her boat appears to have crashed on the southern side of the Island according to her map ("épave")
The western area of the Island is labelled as the "wild coast" (la côte sauvage) on Rousseau's map. It appears to be exposed to west winds (vents d'ouest)
The east coast is also exposed to winds : "roc sous les alizés". "alizés" is the french for "Trade winds".
There is a coral reef on the west of the Island (Récifs coraliens)
Between the crater and the west coast is the "exposed slope" (versant exposé)
Between the coral reef and the ship wreck is the "blued blue lagoon" (lagon bleu azuré)
There are moving sands in the sea (sables mouvants).
On the east of the moving sands is the "Crabs' bay" (la baie des crabes).
The east of the Island is exposed to mosquitos : "Côté des moustiques".
The larger text could correlate to novels considering "The Mosquito Coast" is one by Paul Theroux about a utopian society in Central America and "The Crater" is a novel by James Fenimore Cooper about maritine travels.
Or as this is a fairly common geographical name, it could correspond to another place. See: the Mosquito Coast of Nicaragua and Honduras or the Florida Keys.
The triangle at the bottom of one of her maps around what looks to be an island (labelled les trois) may in fact be a reference to the constellation "Triangulum Australe" or southern triangle.
The map which shows the Island from a side view would suggest that Rousseau has (or had) the ability to leave the mainland of the Island. This is also suggested by the items on the same map which are positioned off the coast. This may be linked to the cable.
This is not strictly true. Using this theory, the map which shows the Island from a top-down view suggests that Rousseau has (or had) the ability to fly, which is highly unlikely.
The lighter spots on the map seem to form a question mark between the north and east arrows.
The top down view map of the Island is very detailed. (I guess if you had 16 years to work on it it should be). However if Rousseau could make a map this detailed, then you would think that she would know a lot more about the Others. Maybe she didn't make the map.
This map shows a crater on the South west side. Half of it is visible in the photo where Sayid is writing on the map.
There appears to be an "X" marked on the beach on the western tip of the Island, and a "2." just inside the cove where Sayid is writing. There also seems to be a "3" toward the back of the cove next to something on the beach.
None of the finer text is readable, although there is text in the cove, and in the valley on the map as well as visible between the silver compass legs.
It can be expected that Sayid would mark the fake Other camp, the statue, and the dock on his map.
The view of the main island from the Hydra Island looks similar to the one on this map, albeit without details such as shoals and sands in between. Could Danielle, or even Alex, have made the map from the vantage point of the Hydra station?