You are absolutely right, you have the right to walk anywhere you want.
"No sheriff, royal official, or other person shall take horses or carts for transport from any free man, without his consent."
Magna Carta, article 30
"No free man shall be seized or imprisoned, or stripped of his rights or possessions, or outlawed or exiled, or deprived of his standing in any other way, nor will we proceed with force against him, or send others to do so, except by the lawful judgement of his equals or by the law of the land."
Magna Carta, article 39
"In future it shall be lawful for any man to leave and return to our kingdom unharmed and without fear, by land or water, preserving his allegiance to us, except in time of war, for some short period, for the common benefit of the realm."
Magna Carta, article 42