Complex sentence: Its solid fortifications are a testament to the innumerable attacks by Spanish, French and English pirates and privateers; the many forts that dot the barrier between land and sea are symbols of the resistance and battles that secured Portuguese independence and national interests.
Split into simpler sentences: Its solid fortifications are a testament to the innumerable attacks by Spanish, French and English pirates and privateers. The many forts that dot the coastline are symbols of the resistance and battles that secured Portuguese independence and national interests.