Herculaneum was buried differently from Pompeii. Hot pyroclastic currents preserved upper floors, timber, food and other organic materials while shifting the ancient shoreline under many metres of deposits.
The archaeological park is a deep excavation beside the modern town of Ercolano. Drainage, groundwater, retaining structures and gradual conservation determine what opens; the ancient beach reopening adds vital evidence about victims and coastline.
Vesuvius access is controlled by the National Park and authorised ticket system. Weather, fire risk, trail conditions and volcanic monitoring can change. The guide does not predict eruptions and directs current risk questions to INGV and Civil Protection.
Give Herculaneum a full day and the volcano a separate weather-dependent day, using official tickets and monitoring sources rather than combining both as a rushed excursion.