Levees and embankments allow humans to c)settle below river level. A levee is defined as "an elongated naturally occurring ridge or artificially constructed fill or wall, which regulates water levels." This definition can also be used for the term embankment.
Australia is an island country, and besides the big main island and Tasmania, it has 12,000 islands plus in its territory. Since it doesn't have any land borders, its borderline is actually the sum of all coastlines of all islands in its territory, and that accounts for 70,000 km.
New South Wales is the biggest state in the country, and it occupies 10% of its total land mass. Its border is 4,635 km, which means that it accounts for 6.62% of the total borderline of Australia.
I think the common between low-latitude countries would be people's skin color and If you compare the Philippines and its neighboring countries, they have more or less similar physical attributes. Typical Filipinos looked similar with Indonesians.
For Southeast Asia, i would also consider religion is common between the two. Both the Philippines and the other Southeast Asian countries such as Indonesia, Malaysia, and Thailand, they have a large number of Muslim settlers while other tropical countries in South America, these countries have similar Spanish ancestry just like the Philippines.