A literal interpretation of 2A would lead us to believe that we can take guns anywhere...
Actually, no. A literal interpretation of the 2A is, literally, that the federal government cannot infringe the people's right to keep and bear arms, for a specific purpose, which is to maintain the freedom of the state. It says nothing about where the people can carry or not carry their guns, it only tells the federal government that IT can't infringe the right. That is all.
...but Supreme Court decisions have stated that although it is an individual citizens right, states maintain the power to legislate its own laws without infringing upon the right of it's citizen's to keep and bear arms. The phrase to bear arms "for the common defence" was struck from the final version for reasons known only to the founding fathers but the term "Militia" has morphed over time to some definition that is subject to the opinion of the moment. After declaring their independence from a tyrranical British government, it's impossible to envision any scenario where the founding fathers were intending to do anything less than bestowing determining powers to the individual states and the citizenry itself. Their desire, and it is evident by reading it, was that the elected Federal Government worked for the people and individual states for the regulation and legislation activities that would benefit and protect it's entire citizenry. The First and Second Amendments positioning within the document clearly illustrate how important the maintaining of these rights were after their own experiences with the British. Our Constitution is a document that all people's worldwide have coveted and we should cherish. A lot of other worldwide governments feel differently, and maybe even our own too often here in recent years.
The US Constitution does not give the federal government the authority to regulate the private ownership and use of guns, and the Second, Nineth and Tenth Amendments serve to further restrict the federal government's voice on the matters of powers retained by the States. The founders derived our US Constitution from British law, most notably from Blackstone's Commentaries, which is the only law they really knew at the time, but the States have always retained the right to exercise some control over the use of guns.
The notion that we can take our guns anywhere we want to go is simply misguided at best. We don't even have the right to go anywhere we want to go, let along take a gun there. The right to self defense, and the obligation to maintain the freedom of the State, is the purpose for the right to keep and bear arms, but that doesn't mean we have the right to take our guns anywhere we want.
At any rate, the Second Amendment is not in any way, nor was it ever intended to be, a license to do anything. It is strictly a restriction placed on the federal government alone. Each state has its own constitution which is written to protect the individual's rights. The US Constitution was never intended to do that. It was meant to inform the federal government that the people have certain rights which it cannot infringe, and the People have the right to protect their rights by force if need be.
The problem, though, is that too many believe a piece of paper was intended, and is going, to stop the government from taking their rights, but it's not true. The people are supposed to defend their rights, but too many are only too willing to give up the power to defend their rights for the perception of security provided by the federal government. That's the "within" referred to as it relates to the fall of America.