The ancient Roman city Petronell Carnuntum and the neighboring town, Bad-Deutsch Altenburg, are located halfway between Vienna and Bratislava to the east. While all that remains of the Roman city are ruins, the tourist companies have poured money into reconstruction to make you think that Carnuntum may still be worth a visit—as if you can go back in time with reenacted gladiator fights. Rather than succumb to the tourist bus, it is far more enjoyable to explore the Roman ruins that haven’t been falsely restored and annotated. Heidentor (which remains a symbol of the city) is the large Roman archway built for Emperor Constantius II. It’s a bit lost in the countryside of wheat fields and windy country highways and is best reached on bike or by car. Similarly, the nearby Carnuntum amphitheater (not to be confused with the tourist site in Bad-Deutsch Altenburg) provides some rock ruins that could provide the setting for a peaceful picnic, and are open to wander through and climb on. Carnuntum and Bad-Deutsch Altenburg could be a peaceful daytrip if you want to go for a bike ride and just enjoy the landscape. Otherwise, stick to the city.