By the late Republic and into the early Principate, bathing within Rome had started to become more complex: Imperial bathing structures, including those of Agrippa, became grander and more and complex. According to some, no public bathing complexes were built for some time as they were felt to host shady activities. Recent studies state that while the building of certain structures was considered virtuous (such as temples, fora, roads, and aqueducts), other structures (brothels, taverns, and other lowly structures) were symbolic of vice. It would appear that public baths occupied a middle ground, "standing somewhere between useful public monuments and lowly havens of corporeal dissipation". This is a likely explanation as to why there were no senatorially decreed bathing complexes during the Republic. Although senators likely did not avoid the baths altogether, they did not want to spend public money on their construction.